Tag: Quantum Computing

Exploring Quantum Computing and Wormholes: A New Frontier

 As we continue to unlock the secrets of quantum gravity and teleportation, each discovery invites us to ponder just how much more there is to unveil, a testament to the infinite possibilities that lie hidden within the quantum tapestry of our universe. The next revelation may be just around the corner, waiting to astonish us all over again, bringing us closer to understanding our universe, and our place within it.

Introduction

Imagine voyaging across the galaxy at warp speed, like in Star Trek or Star Wars, where starships zip through cosmic shortcuts called wormholes. While these cinematic adventures may seem far-fetched, the wildest twist is that wormholes aren’t just a figment of Hollywood’s imagination—quantum physics hints they might truly exist, emerging from the very fabric of quantum entanglement. This remarkable idea flips our understanding of the universe: space and time could actually spring from invisible quantum connections, reshaping what we know about black holes and the universe itself.

This revolutionary perspective burst onto the scene in 2013, thanks to Juan Maldacena and Leonard Susskind, who suggested that whenever two systems are maximally entangled, a wormhole connects them, anchoring each system at opposite ends [1]. Building on the pioneering work of Einstein, Podolsky, and Rosen (EPR) on quantum entanglement and the Einstein-Rosen (ER) description of wormholes, Maldacena and Susskind daringly bridged quantum physics with general relativity, inviting us to think of our universe as far stranger, and far more interconnected, than we ever imagined [2].

Einstein-Rosen Bridges and the Origins of Wormholes

In their seminal paper, Einstein and Rosen encountered the concept of wormholes while seeking to describe space-time and the subatomic particles suspended within it. Their investigation centred on disruptions in the fabric of space-time, originally revealed by German physicist Karl Schwarzschild in 1916, just months after Einstein published his theory of relativity.

Schwarzschild demonstrated that mass can become so strongly self-attractive due to gravity that it concentrates infinitely, causing a sharp curvature in space-time. At these points, the variables in Einstein’s equations escalate to infinity, leading the equations themselves to break down. Such regions of concentrated mass, known as singularities, are found throughout the universe and are concealed within the centres of black holes. This hidden nature means that singularities cannot be directly described or observed, underscoring the necessity for quantum theory to be applied to gravity.

Einstein and Rosen utilized Schwarzschild’s mathematical framework to incorporate particles into general relativity. To resolve the mathematical challenges posed by singularities, they extracted these singular points from Schwarzschild’s equations and introduced new variables. These variables replaced singularities with an extra-dimensional tube, which connects to another region of space-time. They posited that these “bridges,” or wormholes, could represent particles themselves.

Interestingly, while attempting to unite particles and wormholes, Einstein and Rosen did not account for a peculiar particle phenomenon they had identified months earlier with Podolsky in the EPR paper: quantum entanglement. Quantum entanglement led quantum gravity researchers to fixate on entanglement as a way to explain the space-time hologram.

Space-Time as a Hologram

The concept of space-time holography emerged in the 1980s, when black hole theorist John Wheeler proposed that space-time, along with everything contained within it, could arise from fundamental information. Building on this idea, Dutch physicist Gerard ‘t Hooft and others speculated that the emergence of space-time might be similar to the way a hologram projects a three-dimensional image from a two-dimensional surface. This notion was further developed in 1994 by Leonard Susskind in his influential paper “The World as a Hologram,” wherein he argued that the curved space-time described by general relativity is mathematically equivalent to a quantum system defined on the boundary of that space.

A major breakthrough came a few years later when Juan Maldacena demonstrated that anti-de Sitter (AdS) space—a theoretical universe with negative energy and a hyperbolic geometry—acts as a true hologram. In this framework, objects become infinitesimally small as they move toward the boundary, and the properties of space-time and gravity inside the AdS universe precisely correspond with those of a quantum system known as conformal field theory (CFT) defined on its boundary. This discovery established a profound connection between the geometry of space-time and the information encoded in quantum systems, suggesting that the universe itself may operate as a vast holographic projection.

ER = EPR

Recent advances in theoretical and experimental physics have leveraged the SYK (Sachdev-Ye-Kitaev) model to explore the practical realization of wormholes, particularly in relation to quantum entanglement and teleportation. Building on Maldacena’s 2013 insight that suggested a deep connection between quantum entanglement (EPR pairs) and wormhole bridges (ER bridges)—summarized by the equation ER = EPR—researchers have used the SYK model to make these ideas more tangible. The SYK model, which describes a system of randomly interacting particles, provides a mathematically tractable framework that mirrors the chaotic behaviour of black holes and the properties of quantum gravity.

In 2017, Daniel Jafferis, Ping Gao, and Aaron Wall extended the ER = EPR conjecture to the realm of traversable wormholes, using the SYK model to design scenarios where negative energy can keep a wormhole open long enough for information to pass through. They demonstrated that this gravitational picture of a traversable wormhole directly corresponds to the quantum teleportation protocol, in which quantum information is transferred between two entangled systems. The SYK model enabled researchers to simulate the complex dynamics of these wormholes, making the abstract concept of quantum gravity more accessible for experimental testing.

Fig 1. How a quantum computer simulated a wormhole

By 2019, Jafferis and Gao, in collaboration with others, successfully implemented wormhole teleportation using the SYK model as a blueprint for their experiments on Google’s Sycamore quantum processor. They encoded information in a qubit and observed its transfer from one quantum system to another, effectively simulating the passage of information through a traversable wormhole as predicted by the SYK-based framework. This experiment marked a significant step forward in the study of quantum gravity, as it provided the first laboratory evidence for the dynamics of traversable wormholes, all made possible by the powerful insights offered by the SYK model.

Conclusion

Much like the mind-bending scenarios depicted in Hollywood blockbusters such as Star Trek and Star Wars, where spaceships traverse wormholes and quantum teleportation moves characters across galaxies, the real universe now seems to be catching up with fiction.

The remarkable journey from abstract mathematical conjectures to tangible laboratory experiments has revealed a universe far stranger, and more interconnected, than we could have ever imagined. The idea that information can traverse cosmic distances through the fabric of space-time, guided by the ghostly threads of quantum entanglement and the mysterious passageways of wormholes, blurs the line between science fiction and reality.

 As we continue to unlock the secrets of quantum gravity and teleportation, each discovery invites us to ponder just how much more there is to unveil, a testament to the infinite possibilities that lie hidden within the quantum tapestry of our universe. The next revelation may be just around the corner, waiting to astonish us all over again, bringing us closer to understanding our universe, and our place within it.

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Beyond Barriers: How Quantum Tunneling Powers Our Digital and Cosmic World

From memory devices to the heart of stars

Consider the operation of a flash memory card, such as an SSD or USB drive, which is capable of data retention even when powered off; the immense energy output from the sun and stars; or research indicating the occurrence of enzyme catalysis and DNA mutation [1]. These diverse applications are unified by the quantum mechanical phenomenon known as quantum tunneling.

Quantum tunneling refers to the capacity of particles to penetrate energy barriers despite lacking the requisite energy to surpass these obstacles according to classical mechanics. This effect arises from superposition, which imparts wave-like characteristics to quantum-scale particles and permits probabilistic presence across multiple locations. The transmission coefficient, which quantifies the likelihood of tunneling, is determined by the barrier’s height and width, in addition to the particle’s mass and energy [2].

Application of the time-independent Schrödinger equation allows the decomposition of the particle’s wave function into components situated within and outside the barrier. By ensuring continuity of the wave functions at the boundaries, the transmission coefficient can be derived. This theoretical framework has been effectively utilized in various fields, including the development of scanning tunneling microscopes and quantum dots.

Running your digital world

Modern electronics exist in a delicate balance with quantum tunneling. At the heart of today’s microprocessors are advanced transistors, which depend on the quantum ability of electrons to traverse ultra-thin insulating barriers. This tunneling enables transistors to switch on and off at remarkable speeds while using minimal energy, supporting the drive for faster, more energy-efficient devices. As technology advances and the insulating layers within transistors are made thinner to fit more components onto a single chip, the probability of electrons tunneling through these barriers inevitably increases. This leads to unwanted leakage currents, which can generate excess heat and disrupt circuit performance. Such leakage is a major challenge, setting hard physical boundaries on how much further Moore’s law—the trend of doubling transistor density— can be extended.

Yet, the same quantum effect that poses challenges in mainstream electronics is ingeniously exploited in specialized components. Tunnel diodes, for example, are engineered with extremely thin junctions that encourage electrons to quantum tunnel from one side to the other. This property allows tunnel diodes to switch at incredibly high speeds, making them invaluable for high-frequency circuits and telecommunications technologies where rapid response times are essential.

Quantum tunneling is also fundamental to how data is stored in non-volatile memory devices such as flash drives and solid-state drives (SSDs). In these devices, information is retained by manipulating electrons onto or off a “floating gate,” separated from the rest of the circuit by a thin oxide barrier. When writing or erasing data, electrons tunnel through this barrier, and once in place, they remain trapped, even if the device is disconnected from power. This is why your photos, documents, and other files remain safely stored on a USB stick or SSD long after you unplug them.

In summary, quantum tunneling is both a challenge and a tool in modern electronics. Engineers must constantly innovate to suppress unwanted tunneling in ever-smaller transistors, while simultaneously designing components that rely on controlled tunneling for speed, efficiency, and reliable data storage. This duality underscores how quantum mechanics is not merely an abstract scientific theory, but a practical force shaping the infrastructure of everyday digital life.

Powering stars, chips, and qubits

On a cosmic scale, quantum tunneling is fundamental to the process by which stars, including the Sun, emit light. It facilitates the fusion of protons within stellar cores by enabling them to overcome their mutual electrostatic repulsion, thus allowing nuclear fusion to occur at temperatures lower than those required in a strictly classical context. The existence of life on Earth relies on this mechanism, as it powers the energy output of stars that sustain our planet. Insights into tunneling continue to inform research efforts aimed at developing fusion reactors, where analogous physical principles must be managed under controlled conditions rather than governed by stellar gravity.

In superconducting circuits, which comprise materials capable of conducting electric current without resistance, pairs of electrons known as Cooper pairs tunnel through thin insulating barriers called Josephson junctions. When cooled to near absolute zero, these systems enable billions of paired electrons to behave collectively as a single quantum entity. This phenomenon has resulted in devices with exceptional sensitivity for measuring voltage and magnetic fields. Additionally, Josephson junctions play a central role in the architecture of superconducting qubits, where precision control of tunneling between quantum states enables reliable quantum logic operations.

The Nobel Prize in Physics 2025 was awarded to John Clarke, Michael H. Devoret, and John M. Martinis for their pioneering work in designing a macroscopic system utilizing a Josephson junction. The system was composed of two superconductors separated by an ultra-thin oxide layer, only a few nanometers thick. This layer permitted electron tunneling, and the observed discrete energy levels were in complete conformity with quantum mechanical predictions, a notable accomplishment from both experimental and theoretical standpoints [3].

A feature, a bug, and a design principle

Imagine a world where the chemical foundations of life and technology remain a mystery. Without quantum mechanics, our understanding of chemical bonds would be impossibly incomplete, the very medicines that save lives daily could never be designed, and the machines and electronics we rely on in our daily lives would not be possible.

Quantum tunneling stands as a striking testament that quantum phenomena are not mere scientific oddities; they are the bedrock of modern innovation. The same quantum effect that challenges engineers by causing troublesome current leaks in ever-smaller transistors is deliberately harnessed for breakthroughs: non-volatile memory, lightning-fast diodes, atomic-resolution microscopes, and the frontier of quantum computing all depend on it.

Every second, billions of electrons tunnel invisibly within the technology that surrounds you, their quantum behaviour silently orchestrating our digital universe. Far from being an abstract theory, quantum mechanics is the invisible engine driving your phone, your computer, your lasers, and LEDs—the essential infrastructure of twenty-first century life. Our entire technological existence pivots on the strange but real phenomena of the quantum world, challenging us to see science not as distant or esoteric, but as the very substance of our everyday reality.

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Exploring the Implications of Quantum Collapse on Computing

The measurement problem isn’t just theoretical; it directly affects the development of effective quantum computing … Ultimately, reducing errors and increasing algorithm success in quantum computing relies on a solid grasp of what happens during measurement.

Introduction

In quantum mechanics, superposition refers to a unique and intriguing phenomenon where quantum particles can exist in several states simultaneously. Without observation, a quantum system remains in superposition and continues to evolve following Schrödinger’s equation. However, when we measure the system, it collapses into a single, definite state.

This concept challenges our everyday experience with classical objects, which always appear to have specific, identifiable states. Numerous experiments have confirmed that atoms can occupy two or more distinct energy levels at once [1]. If undisturbed, an atom stays in superposition until measurement causes its quantum state to break and settle into one outcome.

But what does it mean to measure or observe a quantum system? Why should a system capable of existing in countless simultaneous states reduce to just one when observed? These fundamental questions form the core of the “measurement problem” in quantum mechanics, a puzzle that has intrigued scientists for over a century since the field was first developed.

The measurement problem

The concept of “measurement,” as addressed by the wave function, has long raised critical questions regarding both the scientific and philosophical underpinnings of quantum mechanics, with significant implications for our comprehension of reality. Numerous interpretations exist to explain the measurement problem, which continues to challenge efforts to establish a coherent and reliable account of the nature of reality. Despite over a century of advancement in quantum mechanics, definitive consensus remains elusive concerning its most fundamental phenomena, including superposition and entanglement.

Quantum mechanics dictates that a quantum state evolves according to two distinct processes: if undisturbed, it follows Schrödinger’s equation; when subjected to measurement, the system yields a classical outcome, with probabilities determined by the Born rule. Measurement refers to any interaction extracting classical information from a quantum system probabilistically, without facilitating communication between remote systems [2]. This framework allows the measurement problem to be categorized into three principal issues:

  • Preferred basis problem – during measurement, outcomes consistently manifest within a particular set of states, although quantum states can, in theory, be described by infinitely many mathematical representations.
  • Non-observability of interference problem – observable interference effects arising from coherent superpositions are limited to microscopic scales.
  • Outcomes problem – measurements invariably produce a single, definitive result rather than a superposition of possibilities. The mechanism behind this selection and its implications for observing superposed outcomes remain unclear.

Addressing any one of these challenges does not fully resolve the others, thereby perpetuating the complexities inherent in the measurement problem.

Wave function collapse

The superposition of an atom across all possible states is characterized by a wave function, which serves as a representation of every quantum state and the probability associated with each state [3]. This function illustrates how an electron within an atomic cloud may occupy various positions with corresponding probabilities, and similarly how a qubit in a quantum computer can be in both states 0 and 1 simultaneously.

In the absence of observation, the system evolves continuously, maintaining the full spectrum of probabilities. Measurement, however, results in a distinct outcome; the act of measurement compels the selection of a single result from myriad possibilities, causing alternative outcomes to cease. As formalized by John von Neumann in 1932, quantum theory reliably predicts the statistical distribution of results over repeated trials, though it remains impossible to forecast the precise outcome of any individual measurement.

The wave function underscores the inherent randomness in the determination of outcomes, akin to nature employing chance. Albert Einstein famously critiqued this perspective, suggesting it implied that “God is playing dice” with the universe. Despite its counterintuitive nature, the wave function is essential for translating the stochasticity of superposition into the observed singular outcome, determined by the probabilities encoded within the wave function.

Conclusion

Wave function collapse plays a key role in quantum mechanics, linking the quantum and classical worlds. This phenomenon lets us measure things like an electron’s position and operate qubits in quantum computers, ensuring accurate results through coherence. Building dependable quantum computers largely depends on managing wave function collapse, aiming to prevent early collapses and errors while encouraging collapses that yield useful data.

The measurement problem isn’t just theoretical; it directly affects the development of effective quantum computing. Quantum algorithms work by sampling from a superposition of computational paths and collapsing them into desired outcomes, especially when designed well. Wave function collapse determines whether qubits are measured as intended or accidentally disrupted by outside influences (decoherence). Ultimately, reducing errors and increasing algorithm success in quantum computing relies on a solid grasp of what happens during measurement.

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The Quantum Realm: Our Connection to the Universe

At the quantum scale, the universe manifests as a field of infinite possibilities, where the electrons within our atoms move in clouds of probability, always shifting. Consequently, we, as humans composed of countless atoms, are an inseparable part of the universe’s ever-changing nature, and our problems, at the quantum level, do not really exist.

Introduction 

When we close our eyes and place our hand on our forehead, we perceive the firmness of our hand and the gentle warmth of our skin. This physical sensation, the apparent solidity and presence of our body, seems tangible and reassuring. However, at the most fundamental level, our bodies are composed almost entirely of empty space. Beneath the surface of our bones, tissues, and cells, we find that our physical form is constructed from atoms, which themselves are predominantly made up of empty space, held together by the invisible forces of electromagnetism. The idea that we are, in essence, built from empty space can feel unsettling, yet it is central to our understanding of quantum mechanics.   

If we imagine an atom, and picture a single proton as a grain of sand placed at the centre of a football stadium, the nearest electron would be found somewhere in the outer bleachers, approximately 90 metres away. The vast expanse between the proton and the electron is filled with nothing but empty space [1]. The electrons themselves do not orbit the nucleus like tiny marbles following a fixed path. Instead, they ripple through space in a cloud-like manner, appearing in one location at one moment, and in another the next. Their movement is not governed by certainty, but by the probability clouds that define their position and momentum.    

The Universe Is Impermanent

Everything in the universe is in a state of constant motion. Objects such as chairs and tables may appear completely motionless to our eyes, yet at the quantum level, this sense of stillness is an illusion. Even as we sleep and perceive ourselves to be at rest, the atoms that make up our bodies are ceaselessly moving and vibrating. This underlying activity is dictated by the principles of quantum mechanics, which reveal an intricate and dynamic world beneath the surface of everyday experience.

Werner Heisenberg’s uncertainty principle states that it is impossible to simultaneously know both the precise position and the exact momentum of any object [2]. The more accurately we measure one, the less certain we become of the other. This fundamental limit means that no object can ever be fixed in a single, definite spot while remaining absolutely still. To do so would violate the laws of quantum physics, which require all matter to retain a degree of movement and uncertainty 

Consider a ball placed in a bowl and cooled until it appears perfectly still at the bottom. According to the uncertainty principle, the ball can never truly be at rest. It will always exhibit a subtle vibration, as restricting its position too precisely leads to uncertainty in its momentum. This perpetual motion is known as the ball’s zero-point energy.  

A universe where everything is perfectly still would not permit life as we know it. Nothing in the cosmos is permanent; particles continuously move, shift, and even appear and disappear. Remarkably, quantum theory predicts that even the vacuum of space is not empty but is filled with modes of vibration possessing zero-point energy [3]. This means that space itself is permeated by an endless and restless sea of energy, where particles are constantly popping in and out of existence, reflecting the ever-changing nature of reality.  

Quantum Mechanics and the Foundations of Consciousness 

At the quantum level, the behaviour of particles is defined by several extraordinary phenomena, including superposition, entanglement, coherence, and the observer effect. In the phenomenon known as superposition, particles can exist in multiple states at the same time. These particles remain in superposition until an act of observation occurs, causing their wave functions to collapse into a single, definite outcome. When two particles interact and become entangled, their properties, such as spin, polarization, and momentum, become fundamentally inseparable. Measurement of one entangled particle instantly determines the state of its partner, regardless of the distance separating them. 

Humans are deeply entangled with the inner workings of the universe. Our thoughts, memories, and emotions are rooted in the quantum behaviours of the atoms that compose our bodies. Consciousness, in this context, is shaped and defined through quantum operations. The billions of neurons firing simultaneously in the human brain function through quantum entanglement, collectively giving rise to our conscious experience [4]. 

Stuart Hameroff and Roger Penrose, in their 1996 paper, argued that consciousness depends on coherent quantum processes within collections of microtubules found in brain neurons. At the lowest neurophysiological level, the cytoskeleton of neurons in the human brain is composed of protein networks, specifically neurofilaments and microtubuli. These structures are essential for various transport processes within neurons [5] [6]. According to Hameroff and Penrose’s theoretical framework, tubulins in microtubuli serve as the substrate for quantum processes. 

Through their Orchestrated Objective Reduction (Orch OR) theory, Hameroff and Penrose proposed that the brain’s microtubules act as quantum computers, maintaining coherent quantum states that collapse in a process tied to the geometry of space-time and influenced by quantum gravity. In this framework, consciousness operates as a quantum wave function passing through the brain’s microtubuli, with these collapses corresponding to the observer’s elementary acts of consciousness and embedding them directly into the fabric of the universe. 

Conclusion 

Contemplating the foundations of our bodies and consciousness, it becomes apparent that quantum mechanics may govern much more than just the biological processes within us. While the Orch OR theory proposed by Hameroff and Penrose remains a topic of debate, it opens the door to the possibility that consciousness arises not solely from biological functions but also from quantum phenomena.

In quantum computing, the act of observation is inherently influential, determining the state to which a particle’s wave function collapses. This raises a profound question: could quantum mechanics provide an explanation for our ability to perceive and realize different realities within our consciousness? Furthermore, could our observation of quantum states, which shape our consciousness, be the very mechanism that connects us to the universe in a holistic manner?

I found that for me, the most meaningful way to think about it was that the concept of uncertainty and constant motion is central to how the universe operates at the quantum level. If our bodies and consciousness are subject to the laws of quantum physics, then our experiences of periods of darkness and despair, feelings of being stuck or hopeless, are never truly fixed states. Motion persists within our atoms and within our consciousness, regardless of our perceptions. The pressure we experience, the everyday stresses, and our emotions are all shaped by how we observe and interpret events. At the quantum level, nothing remains permanent; everything is in flux.

This perspective is not meant to diminish our existence as human beings. Rather, it highlights our intrinsic connection to the fabric of the universe. The universe does not operate with absolute certainty or permanence; it is defined by uncertainty, continual change, and movement. At the quantum scale, the universe manifests as a field of infinite possibilities, where the electrons within our atoms move in clouds of probability, always shifting. Consequently, we, as humans composed of countless atoms, are an inseparable part of the universe’s ever-changing nature, and our problems, at the quantum level, do not really exist.

Designing solutions that effectively meet user needs is the driving force behind my work. I also share practical insights on computing and human-centered design each week. I’d love to connect and discuss your design ideas or challenges; feel free to reach out to me today on LinkedIn or contact me at Mimico Design House.

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Atom Loss: A Bottleneck in Quantum Computing

It was believed that a reliable quantum computer running indefinitely was a decade or more away. With these new advancements in mitigating atom loss, quantum computers running indefinitely and producing reliable results are only a few years away.

Introduction

Until recently, quantum computers have faced a significant obstacle known as ‘atom loss’, which has limited their advancement and ability to operate for long durations. At the heart of these systems are quantum bits, or qubits, which represent information in a quantum state, allowing them to be in the state 0, 1, or both simultaneously, thanks to superposition. Qubits are formed from subatomic particles and engineered through precise manipulation and measurement of quantum mechanical properties.

Historically, this atom loss phenomenon restricted quantum computers to performing computations for only a few milliseconds. Even the most sophisticated machines struggled to operate beyond a few seconds. However, recent breakthroughs by Sandia National Laboratories and Harvard University researchers have changed this landscape dramatically. At Harvard, researchers have built a quantum computer that could sustain operations for over two hours [1], a substantial improvement over previous limitation. This advancement has led scientists to believe they are on the verge of enabling quantum computers to run continuously, potentially without time constraints.

What causes atom loss?

Atom loss presents a significant challenge in quantum computing, as it results in the loss of the fundamental unit of information – the qubit – along with any data it contains. During quantum computations, qubits may be lost from the system due to factors such as noise and temperature fluctuations. This phenomenon can lead to information degradation and eventual system failure. To maintain qubit stability and prevent atom loss, a stringent set of physical, environmental, and engineering conditions must be satisfied.

Environmental fluctuations

Maintaining the integrity of qubits in a quantum computing system is heavily dependent on shielding them from various environmental disturbances. Qubits are highly sensitive to noise, electromagnetic fields, and stray particles, any of which can interfere with their quantum coherence. Quantum coherence describes the ability of a qubit to remain in a stable superposition state over time; the duration of this coherence directly affects how long a qubit can function without experiencing errors.

One fundamental requirement for preserving quantum coherence is the maintenance of cryogenic environments. Qubits must be kept at temperatures near absolute zero, which is essential for eliminating thermal noise and fostering the quantum behaviour necessary for reliable operations. Even slight fluctuations in temperature or the presence of external electromagnetic influences can cause the delicate quantum state of a qubit to degrade or flip unpredictably, leading to information loss and system errors [2].

These stringent environmental controls are critical for ensuring that qubits remain stable and effective throughout quantum computations, highlighting the importance of addressing environmental fluctuations as a key challenge in quantum computing.

Trap imperfections

Neutral atom processors have become a prominent platform for achieving large-scale, fault-tolerant quantum computing [3]. This approach enables qubits to be encoded in states that possess exceptionally long coherence times, often extending up to tens of seconds. The extended coherence time is crucial for maintaining quantum information over prolonged computations, which is essential for complex and reliable quantum operations.

The operation of neutral atom processors relies on the use of optical tweezer arrays. These arrays are dynamically configured, allowing qubits to be trapped in arbitrary geometries and enabling the system to scale to tens of thousands of qubits. The flexibility in configuration and scalability makes neutral atom processors especially suited for advancing quantum computing technology beyond previous limitations.

Despite these advantages, neutral atom processors are not immune to challenges. Atom loss remains a significant issue, arising from several sources. Heating within the system can cause atoms to escape their traps, while collisions with background gas particles further contribute to atom loss. Additionally, during the excitation of an atom from one quantum state to another, such as the transition to a Rydberg state, anti-trapping can occur, leading to the loss of qubits from the processor array.

Readout errors

During the process of reading out quantum information, qubits may be displaced from their positions within the two-dimensional arrays. This readout operation, which involves imaging the qubits to determine their quantum state, can inadvertently lead to the loss of qubits from the processor array. Such atom loss poses a risk to the integrity and continuity of quantum computations.

To address this challenge, neutral atom processor arrays are typically designed with additional qubits that act as a buffer. These extra qubits ensure that, even when some atoms are lost during readout or other operations, enough qubits remain available for the system to continue performing calculations reliably.

Another approach to mitigating atom loss during readout is to slow down the imaging process. By reducing the speed of readout operations, the likelihood of displacing qubits can be minimized, thereby decreasing the rate at which atoms are lost from the array. However, this strategy comes with a trade-off: slowing down readout operations leads to reduced overall system efficiency, as calculations take longer to complete [4]. As a result, there is an inherent balance between maintaining qubit integrity and preserving the speed and efficiency of quantum computations.

Imperfect isolation

Maintaining perfect isolation of qubits from their environment is an immense challenge, primarily because it demands highly sophisticated and costly shielding methods. In practice, it is virtually impossible to completely shield quantum systems from external influences. As a result, stray electromagnetic signals, fluctuations in temperature, and mechanical vibrations can penetrate these defences and interact with quantum systems. Such interactions are detrimental, as they can disrupt the delicate balance required for quantum operations and ultimately lead to atom loss within the processor array [5]. These environmental disturbances compromise the stability and coherence of qubits, posing a significant obstacle to the reliability and scalability of quantum computers.

Recent solutions and research

Multiple research teams are developing ways to reduce atom loss by detecting and correcting missing atoms in quantum systems, improving calculation reliability.

Researchers at Sandia National Laboratories, in collaboration with the University of New Mexico, have published a study demonstrating, for the first time, that qubit leakage errors in neutral atom platforms can be detected without compromising or altering computational outcomes [6]. The team achieved this by utilising the alternating states of entanglement and disentanglement among atoms within the system. In experiments where the atoms were disentangled, results showed substantial deviations compared to those observed during entanglement. This approach enabled the detection of the presence of adjacent atoms without direct observation, thereby preserving the integrity of the information contained within each atom.

Ancilla qubits are essential in quantum error correction and algorithms [7]. These extra qubits help with measurement and gate implementation, yet they do not store information from the main quantum state. By weakly entangling ancilla qubits with the physical qubits, it becomes possible for them to identify errors without disturbing the actual quantum data. Thanks to non-demolition measurements, errors can be detected while keeping the physical qubit’s state intact.

A group of physicists from Harvard University have recently created the first quantum computer capable of continuous operation without needing to restart [1]. By inventing a technique to replenish qubits in optical tweezer arrays as they exit the system, the researchers managed to keep the computer running for more than two hours. Their setup contains 3,000 qubits and can inject up to 300,000 atoms each second into the array, compensating for any lost qubits. This approach enables the system to maintain quantum information, even as atoms are lost and replaced. According to the Harvard team, this innovation could pave the way for quantum systems that can function indefinitely.

Conclusion

It was previously believed that atom loss could seriously hinder the progress of quantum computing. Atom loss and qubit leakage were serious errors that could render calculations unreliable. With the advancements introduced by the researchers at Sandia National Laboratories, the University of New Mexico and Harvard University, and a host of other teams around the world, the revolutionary advancements quantum computers could introduce in scientific research, medicine and finance are becoming closer than ever. It was believed that a reliable quantum computer running indefinitely was a decade or more away. With these new advancements in mitigating atom loss, quantum computers running indefinitely and producing reliable results are only a few years away.

[1] Harvard Researchers Develop First Ever Continuously Operating Quantum Computer

[2] Quantum Chips: The Brains Behind Quantum Computing

[3] Quantum Error Correction resilient against Atom Loss

[4] Novel Solutions For Continuously Loading Large Atomic Arrays

[5] Quantum Decoherence: The Barrier to Quantum Computing

[6] A breakthrough in Quantum Error Correction

[7] Ancilla Qubit

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