Quantum Research

Quantum Theory

Why Has Science Stopped Trying to Understand Quantum Theory?


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Feature image via BBC Future

It is practically a truism that no one really understands quantum mechanics; yet quantum theory reigns as the dominant theory of the very small just as relativity does of the very large. This remains a paradox for a theory so fundamental that it provides the basis for our current understanding of phenomena such as atom decay and why stars shine, as well as how lasers and transistors work, which are embedded in just about everything. Physicists use and rely on quantum theory to predict the outcomes of experiments but they have stopped, as Dr Sean Carroll asserts in a recent op-ed for the New York Times, trying to understand how it works. While there are many contributing factors to this conundrum, a salient inhibitor is the siloed way in which we have come to think about the discipline of science and the way that the modern academic system reflects and perpetuates this way of thinking.

The barriers to understanding quantum begin with the fact that there are some truly sticky bits of theory that simply cannot be accounted for with our existing scientific frameworks. One such example is quantum’s measurement problem: a quantum waveform exists in all states of superposition until it is observed or measured, wherein it collapses into a single position. The fundamental challenge posed by this problem is that science supposes the existence of a measurable, objective world. The centrality of the role of the observer in quantum interactions defies this assumption by asserting that reality is observer-dependent and therefore non-fixed. This idea alone confronts science in a fundamental way, requiring an interpretation of reality that holds space for the “weird” and the “strange” of quantum mechanics—something that mathematics alone has not yet been able to provide.

This issue in quantum physics ignited a deep rift across the brightest minds of physics during the mid 1920s. Albert Einstein, representing the side of the argument which rejected the proposal that the quantum world could be characterized by probabilities rather than certainties, is famously quoted as claiming, “God does not play dice with the universe”. The interpretation of quantum mechanics that prevailed is the Copenhagen Interpretation, which asserts the rather less-than-satisfying conclusion that we simply cannot know more about quantum mechanics than what we can measure using equations. Understanding the theories was thus placed in the “too hard” basket.

Still, divergent theories from quantum’s inception into the 1950’s have attempted to make sense of this phenomenon. These theories had an undeniably philosophical bent and resulted in the majority of postulators being shunned from science altogether. In 1957 for example, Hugh Everett constructed a theory to account for quantum superposition with his Many Worlds Interpretation (MWI). Essentially, Everett’s MWI proposes that for every state of an atom’s superposition in a quantum interaction, that atom simultaneously takes each potential path, creating multiple, coexistent physical realities for each state. Mainstream physicists ridiculed Everett for what they considered to be a scientifically blasphemous postulation, a fact which no doubt contributed to his transition from science to defence analytics shortly after he submitted his dissertation.

Scientists’ resistance toward a multidisciplinary understanding of a scientific problem, however, is a relatively new phenomenon. For centuries, the disciplines of science and philosophy were taken in unity. In fact, the term ‘scientist’ was not even coined until the 19th century. Before that, great names such as Galileo and Newton considered themselves ‘natural philosophers’ rather than ‘scientists’. Even Einstein, Hiesenberg, Dirac and their cohort, the fathers of quantum mechanics, were schooled in European philosophy. This deep understanding of both the “soft” and “hard” sciences influenced their way of thinking, the types of questions they posed and ultimately the theories they constructed. As such, it enabled them to think beyond the boundaries of what was generally accepted information at that time and allowed them to construct new ideas that came to be known as fact.

However, since an epistemological transformation in the 1600-1700’s, which produced the distinction of “science” as the empirical investigation of phenomena, science and philosophy have become increasingly separate disciplines. While it has been a gradual process, this disciplinary divorce has become ingrained in society with the help of most knowledge institutions worldwide, culminating in the propagation of an isolationist understanding of these and other disciplines. This poses a significant challenge to the kind of fruitful multidisciplinary thinking that conceived nearly all of science’s greatest discoveries to date.

Beyond reifying the isolation of disciplines through course structures, universities also play a significant role in shaping academic discovery by prioritising certain areas of research over others. As Carroll elaborates:

“Few modern physics departments have researchers working to understand the foundations of quantum theory. On the contrary, students who demonstrate an interest in the topic are gently but firmly — maybe not so gently — steered away, sometimes with an admonishment to “Shut up and calculate!” Professors who become interested might see their grant money drying up, as their colleagues bemoan that they have lost interest in serious work.”

This situation is compounded by the fact that the metrics by which academic researchers are hired, retained and promoted has undergone a transformation over the last half-century. During this time, research culture has been impacted drastically by the dawn of the Internet, which has enabled an open and thriving, digital research economy. At the same time, an associated shift in focus towards metrics of productivity, quantified largely through research output, has become dominant across knowledge institutions. These changes frame the pervasive expectation that academic researchers should devote a majority of their time to publishing on certain topics and in certain journals in order to remain relevant and successful. Among other challenges, this focus on publication as a distinct metric of notoriety in the academic sciences has led many to game the system, with the resultant focus on quantity of output often detracting from the quality of output.

Aside from this, this phenomenon which has become known in academia as the “publish or perish” culture—that is, the pressure on academics to continuously publish work in order to sustain and further their career in academia—has left academic scientists with little spare time for creative thinking. This modern academic environment has been lamented by Peter Higgs, the scientist who discovered Higgs Boson, who doubts he could have achieved that breakthrough in today’s current academic system:

“It’s difficult to imagine how I would ever have enough peace and quiet in the present sort of climate to do what I did in 1964,” Higgs said. “Today I wouldn’t get an academic job. It’s as simple as that. I don’t think I would be regarded as productive enough.”

Explorative and imaginative thought requires both ample time and space as well as the expectation that by nature of trying new things, it is likely the researcher will encounter far more twists, turns and dead-ends than solutions. While these qualities do not fit well into the “publish or perish” framework, it is well-established that they are of critical value to innovation. Discovery demands that we challenge the very prejudices that have become ingrained in our conceptual structures. In order to do this, one must have the freedom and encouragement to shatter these, rather than be required to work within systems that reinforces them.

Artificial Intelligence, Quantum International Relations, Quantum Research

India Races Toward Quantum Amid Kashmir Crisis


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Amid troubling news of serious human rights violations carried out in India-controlled Jammu and Kashmir—including a debilitating digital blockade lasting over two weeks—Indian Prime Minister Narendra Modi signed an agreement with France for a landmark technological collaboration in quantum and artificial intelligence (AI). The Indo-French collaboration between French company Atos and India’s Centre for Development of Advanced Computing (C-DAC) will establish a Quantum Computing Experience Centre at C-DAC’s headquarters in Pune, India and deliver an Atos Quantum Learning Machine. The high technology partnership, which “advocate[s] a vision of digital technologies that empowers citizens, reduces inequalities, and promotes sustainable development”, sits upon the controversial backdrop of India’s current actions in the Kashmir crisis and presents an interesting view into the intersection of international politics and quantum technologies.

During his first term, Narendra Modi began to position India as a global technology hub, putting its innovation sector on the map by embracing international investment and collaboration. The advancements that have been made over the last five years as a result of these activities have helped to fuel India’s socioeconomic development and cement its place on the global stage as a major emerging economy with a vibrant technology sector. Now in his second term, Modi seeks to apply a digital taxation to global technology giants like Google and Facebook on their activities in India. Though this policy shift has been identified as a potential barrier to Big Tech’s incentive to contribute to India’s start-up space, Modi has nevertheless continued to cultivate a tech-forward name for his government. His “New India” government focuses on sustainable development and emerging technologies, especially agricultural technology, AI and quantum.

Within this context, India’s national quantum technology research and development capacity has blossomed at a rapid pace, especially with regard to quantum mechanical theory and theoretical physics research and software development. However, unlike the top competitors in quantum computing such as China and the U.S., India lacks a strong quantum computing hardware industry, a challenge which could be exacerbated by Modi’s Big Tech taxation policy. In order to supplement research activities in its burgeoning quantum and AI sectors, Modi has instead turned toward collaboration with international governments as a vehicle to boost domestic technological development. For example, India’s recently established fund-to-fund partnership with Japan will support over 100 start-ups in AI and IoT. Likewise, the new Indo-French partnership is a critical piece of the puzzle for India, promising to help boost its national deficiency in applied quantum computing development and help India to become a leader in the quantum space.

With international partnerships playing such a key role in Modi’s plan for the development and growth of India’s quantum computing and AI industries, there is a sense that the country’s actions in state-controlled Jammu and Kashmir are damaging its international reputation. This perspective, however, is demonstrably negated by the signing of the Indo-French bilateral agreement. The agreement, which stipulates French alignment with India as a partner in sustainable development and emerging technologies, outlines the countries’ shared commitment to “an open, reliable, secure, stable and peaceful cyberspace”. It was signed into existence even as India, the world leader in internet shutdowns, enacted a digital lockdown on Kashmir for the 51st time in 2019 alone. This data sits in stark contrast to the stated objectives of the partnership and demonstrates the separation of business from peace-building priorities on an international scale.

The Kashmir conflict, a turbulent territorial dispute between India, Pakistan and China, dates back to the partition of 1947 and has already incited four wars between India and Pakistan. Kashmir, dubbed one of the world’s most militarized zones, is of strategic value to both countries and is India’s only Muslim-majority region. The recent conflict was spurred by a series of brutal attacks and rebellions since February 2019, which ultimately led the Modi government to revoke India-controlled Kashmir’s “special status” of autonomy granted under Article 370 of the Indian constitution. Given this complex history and characterization, India’s fresh assault on the region has led many (including Pakistan’s own Prime Minister) to fear an escalation of violence that could result in a worst-case-scenario nuclear face-off between India and Pakistan.

Whether or not it is representative of the true feelings of Modi’s “New India”, Indian national media has expressed nearly unequivocal supportive of the revocation of Article 370. French comments, however, lean toward neutrality—tactfully holding the situation at arm’s length while urging for a bilateral negotiation between India and Pakistan. Regardless of the two countries coming to a peaceful resolution or not, it appears that international investment in Indian quantum and AI development shall not waver in the face of the Kashmir conflict. Ironically, as India sprints to catch up in the quantum race with the support of France and other international allies, the results of the past technological nuclear arms “race” looms heavy over the continent.

Quantum Internet, Quantum Research

Quantum Teleportation: Paving the Way for a Quantum Internet


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Last week’s big quantum news centred on two proof of concept studies, both of which claim to have achieved quantum teleportation using a tripartite unit of quantum information called a qutrit, for the first time. While quantum teleportation has been demonstrated previously, it has only been carried out with qubits, which are capable of storing less information than qutrits but thought to be more stable. The novel feat was achieved independently by two teams, one led by Chinese physicist Guang-Can Guo at the University of Science and Technology of China (USTC) and the other, an international collaboration headed by Anton Zeilinger of the Austrian Academy of Sciences and Jian-Wei Pan of USTC. While both teams have reported their results in preprint articles, the article by the Austrian-led team has been accepted for publication in Physical Review Letters.

Competition for credit of this achievement aside, the team’s findings ultimately support each other in substantiating an advancement in quantum teleportation theory: namely, that quantum networks should be capable of carrying far more information with less interference than previously thought. This advancement—like many in the world of quantum—is likely to be found most exciting for physicists, evading the grasp of an applied significance for those of us with less scientific minds. Nevertheless, the notion of quantum teleportation has once again grabbed headlines and imaginations, providing a good opportunity to explore the concept and the applied significance that advancements like this might eventually have on our world.

While it may sound flash, quantum teleportation is an affair less akin to science fiction than one might imagine. On a basic level, quantum teleportation differs from ‘Star Trek teleportation’ because it is used to transmit information rather than macroscale physical objects, like human beings. This is possible because of quantum entanglement, a phenomenon of quantum physics that allows us to look at one particle or group of particles and know things about another, even if those particles are separated by vast distances. Quantum teleportation relies on entanglement to transfer information based on this shared state of being demonstrated by entangled particles. As such, quantum teleportation can be defined as “the instantaneous transfer of a state between particles separated by a long distance”.

Quantum teleportation holds the most obvious promise in the discipline of quantum communication, where its impact in secure communication was established as early as 1997. In 2017, Chinese scientists working with a team in Austria made waves with their announcement that they had achieved transnational quantum teleportation, establishing a quantum-secure connection for a video conference between the Chinese Academy of Sciences in Beijing and the Austrian Academy of Sciences in Vienna, some 7,600 kilometres away from each other. The experiment utilized China’s Micius satellite to transmit information securely using photons. Micius is a highly sensitive photon receiver, capable of detecting the quantum states of single photons fired from the ground. These photons, beamed via Micius, acted as qubits, allowing researchers in both countries to access a shared quantum key and thus enabling them to participate in the quantum-encrypted video call. Critically, should the data have been accessed by a third party, the code would be scrambled, leaving evidence of tampering for researchers at both ends of the connection.

This experiment, facilitated by quantum teleportation, proved two fundamental and impactful theories in quantum physics: that quantum communication can provide a previously unfathomable level of security and that it is capable of doing so on a global scale. Given these capabilities and coupled with the new qutrit proof-of-concept work, the realm of applied possibilities for quantum teleportation is expanding.

Aside from ultra-secure, transcontinental video conferences, one very hyped application for quantum teleportation is in the development of a hyper-fast quantum internet. Due to the entangled state of particles, information is transmitted instantaneously in quantum teleportation—faster than the speed of light. However, the transfer of this information is still required to operate within the current confines of classical communication. As such, even quantum information must travel through ground-based fibre optic cables or via photon-sensitive space-based satellites, like China’s Micius. This infrastructure is both expensive and potentially expansive, posing a formidable challenge for a global roll-out of a quantum internet. Still, these early experiments have laid the groundwork for the development of a quantum-secure Wi-Fi by putting theory to the test and producing promising results.

Currently, a team of researchers at Delft University in the Netherlands is working to build a quantum network, using quantum teleportation as the mode of transport for information between linkage points. The project, which aims to connect four cities in the Netherlands, is scheduled for completion in 2020. In China too, researchers are constructing the backbone for a quantum network to connect Beijing and Shanghai. Aside from the support of private corporations such as banks and other commercial entities, progress on the concept of both localised and international quantum networks has been spurned by pressing anxiety about global levels of cybersecurity

A critical advantage to a future quantum internet is the enhanced security afforded by quantum teleportation—the ability to create an unhackable connection. This could have serious implications for national security and could present a potential solution for many foreign surveillance and interference challenges that countries face today. For example, it is now public knowledge in the U.S. that Russia has the demonstrative ability to directly interfere with most paperless voting systems. While states are currently reticent about making changes to the current U.S. vote-casting system, alternatives are slowly being considered—from regressive paper ballot casting to progressive blockchain applications—in order to safeguard American votes against hacking efforts. Quantum teleportation could offer an interesting alternative in this space as the technology continues to develop.

Though quantum teleportation will not be transporting human beings between planets any time soon, it will play a key role in ushering in an internet revolution. While it remains to be seen exactly how that revolution will play out, it is clear that it will bring an unprecedented level of security and speed to global communications. It is also apparent that the level of interest in the secure and high-speed communications afforded through quantum teleportation is broad and deep, spanning both public and private sectors across the globe. Quantum teleportation has recently seen a number of experimental proofs, pushing the field of quantum communications to the fore of quantum development and promising to deliver a much sought-after security transformation within the decade.

Quantum Computing, Quantum Research

Saving Schrödinger’s Cat: Researchers Discover an Early Warning Signal for Quantum Jumps


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Feature image via Science X.

Gabriella Skoff

Schrödinger’s cat is a thought experiment that has become well known as a symbol for the “weirdness” and unpredictability of the phenomenon of quantum superposition. The eponymous thought experiment devised by Austrian physicist Erwin Schrödinger in 1935 involves a cat, a vial of poison, a radioactive substance and a sealed box. The experiment dictates that if an atom of the radioactive substance decays then it will trigger the release of the poison, killing the cat; however, that may or may not happen. One can only find out if this has occurred, and therefore if the cat is alive or dead, by opening the box to observe the state of being of the cat. According to the Copenhagen Interpretation of quantum physics, until the observer peeks inside the box, the cat is actually both dead and alive. It is only when the state of the cat is observed, therefore, that the quantum superposition collapses into one or the other states and the cat is found to be either dead or alive.

Based on Niels Bohr’s 1913 proposal of quantum jumps, it was thought that the process of the cat collapsing into a theoretically dead or alive state upon observation was both instantaneous and unpredictable. However, new experimental research performed by a team of Yale researchers and published last week in Nature journal, suggests otherwise. Dr Zlatko Minev and his team’s findings conclude that a quantum jump does not actually exhibit the random, abruptness that defines the fate of Schrödinger’s cat. Rather, their research suggests, “the evolution of each [quantum] jump is continuous, coherent and deterministic”.

Within the context of Schrödinger’s cat paradox, these findings imply that the continued-life/death of the cat is simply the final stage of a process rather than an instant occurrence without foreshadowing. Further, the Yale team has detected “an advance warning signal” which indicates that a jump is about to occur. This seems to signify that we can not only detect when a quantum jump will occur but that we can also potentially reverse it during the transition. These new findings not only impact our theoretical ability to potentially save Schrödinger’s cat from its proverbial death but also have a fundamental impact in applied quantum computing.

The conundrum of a quantum jump has long presented a challenge in the applied field of quantum computing, where a jump in qubits manifest as an error in calculations. Researchers are hopeful that these new findings could potentially facilitate major advances in understanding and controlling quantum information. They anticipate that this new discovery will help to develop an early warning system that can predict when a jump, and therefore a computational error, is about to occur in order to catch it before it happens and reverse its course. While it would be a wonderful conclusion that Schrödinger’s dear cat could be saved, the real value of this research lies in its applied context: the potential to develop an advanced monitoring, detection and correction function for quantum systems, which could help bring us one step closer to a quantum advantage.

 

 

Quantum Research

The Quantum Question of an Objective Reality


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Rick and Morty explore the multiverse, a spin on the Many Worlds Interpretation.
Image via Adult Swim

Gabriella Skoff

Thought experiments in the domain of quantum physics have long captured the public imagination with their strange and “spooky” nature. Schrödinger’s at once dead-and-alive cat and its lesser-known extension, Eugene Wigner’s eponymous Wigner’s Friend, are two famous thought experiments which examine the concept of superposition and the role of the observer in quantum interactions. Until very recently, quantum technologies were simply not advanced enough to replicate Wigner’s Friend and an experiment modelled on Schrödinger’s Cat would no doubt raise serious ethical concerns for animal rights. As such, since their inception these thought experiments have been relegated to the realm of theory and imagination.

That changed last week, when Massimiliano Proietti and his team at Heriot-Watt University in Edinburgh succeeded in performing an experiment modelled on the Wigner’s friend scenario in a laboratory setting. Through this experiment, the researchers sought to explore what is known as the measurement problem—the question of how, and if, the wave function collapse occurs—the central problem in quantum mechanical interpretations.

Using the groundwork previously laid by researchers from the University of Vienna in Austria, the Edinburgh team carried out an extension of the Wigner’s Friend scenario using a “state-of-the-art 6 photon experiment”. The researchers used six entangled photons to simulate a scenario in which the role of both Wigner and his friend were occupied by measuring equipment instead of scientists. As in the thought experiment: “Wigner’s friend measures the polarization of a photon and stores the result. Wigner then performs an interference measurement to determine if the measurement and the photon are in a superposition.”

The experimental setup, as depicted by the researchers. image via
arxiv.org/abs/1902.05080 

The as yet unpublished results prove Wigner’s theory correct. The researcher’s findings suggest that two observers of a quantum interaction can observe two different realities, which are both equally real and correct simultaneously, even if they contradict each other. The implication of this assertion is that in quantum physics there is no objective reality; that reality itself is observer-dependent. The authors of the study suggest that these results necessitate an evolution in our understanding of quantum theory, a shift toward theoretical frameworks that are observer-dependent and away from interpretations that are not.

The impact of this conclusion, which proposes an unconventional interpretation of the notion of reality, could extend far beyond the discipline of physics.

Strikingly, the assumption that multiple, contradictory realities can coexist calls the concept of objective fact—the very pursuit of science itself—into question. This point, posed in an article by the MIT Tech Review, jeopardizes the assumption of the existence of “universal facts”. How might an understanding of the world around us, in which there is no shared, objective reality, change not just science but also social theory?

Of course, it is hasty to argue that quantum theory applies seamlessly to the social world, suggesting there is a direct, logical mapping. Thus far, the topic of how the microscopic quantum world effects our macroscopic, visible world has not been fully explored through research. That does not mean, however, that there is no symmetry. The question of the universality of quantum theory continues to permeate thinking today, much as it had captured the imagination of quantum theorists in the early 1900’s.

Schrödinger’s Cat (1935), for example, explores the question of the relationship between quantum and classical reality. Among other revelations, this thought experiment suggests that projecting nanoscale quantum theory onto a macro-scale experiment produces logic-defying results, ultimately leading to the conclusion that a cat cannot be both alive and dead at the same time. Schrödinger wished to argue that the dominant Copenhagen Interpretation of quantum physics, which states that an object in a state of quantum superimposition can exist in all possible configurations, does not hold at the macroscale.

Nevertheless, this problem posed by the Copenhagen Interpretation, considered by Schrödinger to be settled by his theoretical experiment, persists.

The findings of the Edinburgh team suggest that in fact Schrödinger’s cat can be both dead and alive at the same time, leading to a whole new set of questions and theories. One way to accommodate for the experiment’s result, the authors write: “…is by proclaiming that “facts of the world” can only be established by a privileged observer—e.g., one that would have access to the “global wavefunction” in the many worlds interpretation or Bohmian mechanics.”

As the authors suggest, this research potentially validates the Many-Worlds Interpretation (MWI). The MWI, as the name suggests, stipulates that each quantum interaction produces not just one result but all possible results, which exist simultaneous, branching off to form different versions of reality and producing many independent histories, futures and worlds. The researchers propose that in order for the concept of objective reality to function in the context of their findings, the holder of that knowledge must, in a godlike fashion, have access to all information from every possible reality.

Scientific theory produces claims at knowing and understanding the world around us as it really is. Quantum physics, however, has the potential to unravel this by posing the most fundamental question of all: What is reality?