Lifeboat Foundation

An international team of physicists has shown experimentally for the first time how a Bose-Einstein condensate — tens of thousands of quanta of ‘liquid light’ — is formed in the thinnest monatomic film of a semiconductor crystal. The team includes the head of the Spin Optics Laboratory at St Petersburg University, Professor Alexey Kavokin. This discovery will help create new types of lasers capable of producing qubits — the main integral parts of quantum computers of the future.

Researchers at ETH Zurich have succeeded in turning specially prepared graphene flakes either into insulators or into superconductors by applying an electric voltage. This technique even works locally, meaning that in the same graphene flake regions with completely different physical properties can be realized side by side.

The production of modern electronic components requires materials with very diverse properties. There are isolators, for instance, which do not conduct electric current, and superconductors which transport it without any losses. To obtain a particular functionality of a component one usually has to join several such materials together. Often that is not easy, in particular when dealing with nanostructures that are in widespread use today.

A team of researchers at ETH Zurich led by Klaus Ensslin and Thomas Ihn at the Laboratory for Solid State Physics have now succeeded in making a material behave alternately as an insulator or as a superconductor – or even as both at different locations in the same material – by simply applying an electric voltage. Their results have been published in the scientific journal Nature Nanotechnology. The work was supported by the National Centre of Competence in Research QSIT (Quantum Science and Technology).

As the digital revolution has now become mainstream, quantum computing and quantum communication are rising in the consciousness of the field. The enhanced measurement technologies enabled by quantum phenomena, and the possibility of scientific progress using new methods, are of particular interest to researchers around the world.

Recently two researchers at Tampere University, Assistant Professor Robert Fickler and Doctoral Researcher Markus Hiekkamäki, demonstrated that two–photon interference can be controlled in a near-perfect way using the spatial shape of the photon. Their findings were recently published in the prestigious journal Physical Review Letters.

“Our report shows how a complex light-shaping method can be used to make two quanta of light interfere with each other in a novel and easily tuneable way,” explains Markus Hiekkamäki.

In 1884, Edwin Abbott wrote the novel Flatland: A Romance in Many Dimensions as a satire of Victorian hierarchy. He imagined a world that existed only in two dimensions, where the beings are 2D geometric figures. The physics of such a world is somewhat akin to that of modern 2D materials, such as graphene and transition metal dichalcogenides, which include tungsten disulfide (WS₂), tungsten diselenide (WSe₂), molybdenum disulfide (MoS₂) and molybdenum diselenide (MoSe₂).

Modern 2D materials consist of single-atom layers, where electrons can move in two dimensions but their motion in the third dimension is restricted. Due to this ‘squeeze’, 2D materials have enhanced optical and electronic properties that show great promise as next-generation, ultrathin devices in the fields of energy, communications, imaging and quantum computing, among others.

Typically, for all these applications, the 2D materials are envisioned in flat-lying arrangements. Unfortunately, however, the strength of these materials is also their greatest weakness—they are extremely thin. This means that when they are illuminated, light can interact with them only over a tiny thickness, which limits their usefulness. To overcome this shortcoming, researchers are starting to look for new ways to fold the 2D materials into complex 3D shapes.

John Martinis has done groundbreaking research on coherent superconducting devices since his PhD at the University of California, Berkeley, in 1985. These superconducting devices can be modeled as lumped-element electric circuits using Josephson junctions, capacitors and inductors as components. The fact that a superconducting phase across a Josephson junction can display coherent quantum behavior – even though it is a property of the wave function of an immense number of electrons – can be viewed as a fundamental discovery [1], kickstarting, in retrospect, the field of superconducting quantum computing.

John Martinis invented and developed the superconducting phase qubit, based on a current-biased Josephson junction, for the purpose of scalable multi-qubit quantum computing [2]. In 2002, he first demonstrated coherent Rabi oscillations and quantum measurement for such superconducting phase qubit [3]. He has had a longstanding interest in understanding the origin of noise in superconducting electric circuits as these sources of noise naturally limit qubit coherence. In particular, his understanding of noise sources such as dielectric loss, flux noise and the presence and dynamics of quasi-particles [4], by means of simple physical models, have been instrumental in the field. The effect and mitigation of quasi-particles and how they are affected by radiation and cosmic rays continues to be of high interest for the future of superconducting quantum devices [5, 6].

An important step showing his leadership and commitment to building a quantum computer came with his 2014 move, as a Professor at UCSB, to Google, where he gathered a large team of physicists and engineers to tackle the challenge of making a multi-qubit programmable processor. This team has excelled in its relentless focus on optimizing device performance by implementing successful engineering choices for qubit design, couplers and scalable I/O.

Local media reports quoted Wang as saying that artificial intelligence, 6G, quantum technology, driverless vehicles, intelligent networks and other “frontier areas” would be the focus of Shenzhen’s investment plans, while the value of its digital economy would account for more than 31 per cent of GDP by 2025.

Money will be used to support innovation in core technologies, city’s Communist Party chief Wang Weizhong says.

A team of Chinese physicists are making some serious progress in the field of quantum mechanics. Recently, this team has measured the speed of quantum entanglement – more affectionately known as “spooky action at a distance”, as Einstein called it.

To summarize quantum entanglement, two or more particles are entangled, which means they share the same wave form. The more technical definition is: “Quantum entanglement occurs when particles such as photons, electrons, molecules as large as buckyballs, and even small diamonds interact physically and then become separated; the type of interaction is such that each resulting member of a pair is properly described by the same quantum mechanical description (state), which is indefinite in terms of important factors such as position, momentum, spin, polarization, etc.”

When most people describe this interesting process, they’ll describe the information transfer as ‘instantaneous’ or ‘near-instantaneous’. Several research teams have attempted to measure the actual speed seen in the transfer of information in entangled systems, but have failed in one way or another, usually resulting from flawed methodology dealing in quantum nonlocality.

Quantum entanglement is the binding together of two particles or objects, even though they may be far apart – their respective properties are linked in a way that’s not possible under the rules of classical physics.

It’s a weird phenomenon that Einstein described as “spooky action at a distance”, but its weirdness is what makes it so fascinating to scientists. In new research, quantum entanglement has been directly observed and recorded at the macroscopic scale – a scale much bigger than the subatomic particles normally associated with entanglement.

The dimensions involved are still very small from our perspective – these experiments involved two tiny aluminum drums one-fifth the width of a human hair – but in the realm of quantum physics they’re absolutely huge.

Forty years ago, IBM researcher Charlie Bennett helped usher in the study of quantum mechanics’ impact on computing. IBM is still at it—and so is Bennett.