Lifeboat Foundation

😀 2011

Trevor D. Rhone, Dwipesh Majumder, Brian S. Dennis, Cyrus Hirjibehedin, Irene Dujovne, Javier G. Groshaus, Yann Gallais, Jainendra K. Jain, Sudhansu S. Mandal, Aron Pinczuk, Loren Pfeiffer, and Ken West. 2011. “Higher-Energy Composite Fermion Levels in the Fractional Quantum Hall Effect.” Phys. Rev. Lett., 106, Pp. 096803.

Early in its history, computing was dominated by time-sharing systems. These systems were powerful machines (for their time, at least) that multiple users connected to in order to perform computing tasks. To an extent, quantum computing has repeated this history, with companies like Honeywell, IBM, and Rigetti making their machines available to users via cloud services. Companies pay based on the amount of time they spend executing algorithms on the hardware.

For the most part, time-sharing works out well, saving companies the expenses involved in maintaining the machine and its associated hardware, which often includes a system that chills the processor down to nearly absolute zero. But there are several customers—companies developing support hardware, academic researchers, etc.—for whom access to the actual hardware could be essential.

The fact that companies aren’t shipping out processors suggests that the market isn’t big enough to make production worthwhile. But a startup from the Netherlands is betting that the size of the market is about to change. On Monday, a company called QuantWare announced that it will start selling quantum processors based on transmons, superconducting loops of wire that form the basis of similar machines used by Google, IBM, and Rigetti.

A team of researchers affiliated with multiple institutions in China, working at the University of Science and Technology of China, has achieved another milestone in the development of a usable quantum computer. The group has written a paper describing its latest efforts and have uploaded it to the arXiv preprint server.

Back in 2019, a team at Google announced that they had achieved “quantum supremacy” with their Sycamore machine—a 54 qubit processor that carried out a calculation that would have taken a traditional computer approximately 10000 years to complete. But that achievement was soon surpassed by other teams from Honeywell and a team in China. The team in China used a different technique, one that involved the use of photonic qubits—but it was also a one-trick pony. In this new effort, the new team in China, which has been led by Jian-Wei Pan, who also led the prior team at the University of Science and Technology has achieved another milestone.

The new effort was conducted with a 2D programable computer called Zuchongzhi—one equipped to run with 66 qubits. In their demonstration, the researchers used only 56 of those qubits to tackle a well-known computer problem—sampling the output distribution of random quantum circuits. The task requires a variety of computer abilities that involve mathematical analysis, matrix theory, the complexity of certain computations and probability theory—a task approximately 100 times more challenging than the one carried out by Sycamore just two years ago. Prior research has suggested the task set before the Chinese machine would take a conventional computer approximately eight years to complete. Zuchongzhi completed the task in less than an hour and a half. The achievement by the team showed that the Zuchongzhi machine is capable of tackling more than just one kind of task.

In 2015, after 85 years of searching, researchers confirmed the existence of a massless particle called the Weyl fermion. With the unique ability to behave as both matter and anti-matter inside a crystal, this quasiparticle is like an electron with no mass. The story begun in 1928 when Dirac proposed an equation for the foundational unification of quantum mechanics and special relativity in describing the nature of the electron. This new equation suggested three distinct forms of relativistic particles: the Dirac, the Majorana, and the Weyl fermions. And recently, an analog of Weyl fermions has been discovered in certain electronic materials exhibiting a strong spin orbit coupling and topological behavior. Just as Dirac fermions emerge as signatures of topological insulators, in certain types of semimetals, electrons can behave like Weyl fermions.

These Weyl fermions are what can be called quasiparticles, which means they can only exist in a solid such as a crystal, and not as standalone particles. However, as complex as quasiparticles sound, their behavior is actually much simpler than that of fundamental particles, because their properties allow them to shrug off the same forces that knock their counterparts around. This discovery of Weyl fermions is huge, not just because there is finally a proof that these elusive particles exist, but because it paves the way for far more efficient electronics, and new types of quantum computing. Weyl fermions could be used to solve the traffic jams with electrons in electronics. In fact, Weyl electrons can carry charges at least 1000 times faster than electrons in ordinary semiconductors, and twice as fast as inside graphene. This could lead to a whole new type of electronics called ‘Weyltronics’.

The development is being compared to the desktop computing system revolution of the 1960’s.

For the first time ever, a single SoC features both quantum and Turing-based computing — and includes the world’s first hardware-agnostic quantum OS.

Quantum computing algorithms can simulate infinitely-large quantum systems thanks to mathematical tools known as tensor networks.

Scientists have succeeded in combining two exciting material types together for the very first time: an ultrathin semiconductor just a single atom thick; and a superconductor, capable of conducting electricity with zero resistance.

Both these materials have unusual and fascinating properties, and by putting them together through a delicate lab fabrication process, the team behind the research is hoping to open up all kinds of new applications in classical and quantum physics.

Semiconductors are key to the electrical gadgets that dominate our lives, from TVs to phones. What makes them so useful as opposed to regular metals is their electrical conductivity can be adjusted by applying a voltage to them (among other methods), making it easy to switch a current flow on and off.

A new laser that generates quantum particles can recycle lost energy for highly efficient, low threshold laser applications.

Scientists at KAIST have fabricated a laser system that generates highly interactive quantum particles at room temperature. Their findings, published in the journal Nature Photonics, could lead to a single microcavity laser system that requires lower threshold energy as its energy loss increases.

The system, developed by KAIST physicist Yong-Hoon Cho and colleagues, involves shining light through a single hexagonal-shaped microcavity treated with a loss-modulated silicon nitride substrate. The system design leads to the generation of a polariton laser at room temperature, which is exciting because this usually requires cryogenic temperatures.

A new analysis of black hole vibrational spectra identifies which frequencies are stable to perturbations—information pertinent for gravitational-wave analysis and quantum gravity modeling.

Are black holes stable when they are slightly perturbed? This question was answered 50 years ago by the physicist C. V. Vishveshwara with a numerical experiment: Vishveshwara imagined sending a wave packet toward a black hole and observing what came out [1]. He found that the scattered wave is a sum of damped sinusoids, whose frequencies and damping times are the free-vibration modes, or so-called quasinormal modes, of the black hole. The damping implies that black holes are stable—they settle back into a stationary state after being perturbed.