Lifeboat Foundation

So-called “higher symmetries” are illuminating everything from particle decays to the behavior of complex quantum systems.

RIKEN physicists have created an exotic quantum state in a device with a disk-like geometry for the first time, showing that edges are not required. This demonstration opens the way for realizing other novel electronic behavior. Their findings are published in Nature Physics.

Physics has long moved on from the three classic states of matter: solid, liquid and gas. A better theoretical understanding of quantum effects in crystals and the development of advanced experimental tools to probe and measure them has revealed a whole host of exotic states of matter.

A prominent example of this is the topological insulator: a kind of crystalline solid that exhibits wildly different properties on their surfaces than in the rest of the material. The best-known manifestation of this is that topological insulators conduct electricity on their surfaces but are insulating in their interiors.

Quantum computers have the potential to break common cryptography techniques, search huge datasets and simulate quantum systems in a fraction of the time it would take today’s computers. But before this can happen, engineers need to be able to harness the properties of quantum bits or qubits.

Currently, one of the leading methods for creating qubits in materials involves exploiting the structural atomic defects in diamond. But several researchers at the University of Chicago and Argonne National Laboratory believe that if an analogue defect could be engineered into a less expensive material, the cost of manufacturing quantum technologies could be significantly reduced. Using supercomputers at the National Energy Research Scientific Computing Center (NERSC), which is located at the Lawrence Berkeley National Laboratory (Berkeley Lab), these researchers have identified a possible candidate in aluminum nitride. Their findings were published in Nature Scientific Reports.

“Silicon semiconductors are reaching their physical limits—it’ll probably happen within the next five to 10 years—but if we can implement qubits into semiconductors, we will be able to move beyond silicon,” says Hosung Seo, University of Chicago Postdoctoral Researcher and a first author of the paper.

The first 100 people to use code UNIVERSE at the link below will get 60% off of Incogni: https://incogni.com/universe.

Researched and Written by Colin Stuart.
Check out his superb Astrophysics for Beginners course here: https://www.colinstuart.net/astrophysics-course-for-beginner…on-online/

Continue reading “Is Time Travel Possible In Our Universe?” »

There are loopholes.

Try out my quantum mechanics course (and many others on math and science) on Brilliant using the link https://brilliant.org/sabine. You can get started for free, and the first 200 will get 20% off the annual premium subscription.

Continue reading “I Think Faster Than Light Travel is Possible. Here’s Why” »

Accelerating Leadership In Quantum Information Sciences — Dr. Charles Tahan, Ph.D., Assistant Director for Quantum Information Science (QIS); Director, National Quantum Coordination Office, Office of Science and Technology Policy, The White House.

Dr. Charles Tahan, Ph.D. is the Assistant Director for Quantum Information Science (QIS) and the Director of the National Quantum Coordination Office (NQCO) within the White House Office of Science and Technology Policy (https://www.quantum.gov/nqco/). The NQCO ensures coordination of the National Quantum Initiative (NQI) and QIS activities across the federal government, industry, and academia.

Continue reading “Dr. Charles Tahan, Ph.D. — Director, National Quantum Coordination Office — OSTP, The White House” »

Goodbye phone lines. Hello quantum physics.

A new approach shrinks quantum photonic technology to the size of a Euro coin.

face_with_colon_three year 2017.

First observed in liquid helium below the lambda point, superfluidity manifests itself in a number of fascinating ways. In the superfluid phase, helium can creep up along the walls of a container, boil without bubbles, or even flow without friction around obstacles. As early as 1938, Fritz London suggested a link between superfluidity and Bose–Einstein condensation (BEC)³. Indeed, superfluidity is now known to be related to the finite amount of energy needed to create collective excitations in the quantum liquid^4,5,6,7, and the link proposed by London was further evidenced by the observation of superfluidity in ultracold atomic BECs^1,8. A quantitative description is given by the Gross–Pitaevskii (GP) equation^9,10 (see Methods) and the perturbation theory for elementary excitations developed by Bogoliubov¹¹. First derived for atomic condensates, this theory has since been successfully applied to a variety of systems, and the mathematical framework of the GP equation naturally leads to important analogies between BEC and nonlinear optics^12,13,14. Recently, it has been extended to include condensates out of thermal equilibrium, like those composed of interacting photons or bosonic quasiparticles such as microcavity exciton-polaritons and magnons^14,15. In particular, for exciton-polaritons, the observation of many-body effects related to condensation and superfluidity such as the excitation of quantized vortices, the formation of metastable currents and the suppression of scattering from potential barriers^{2,16,17,18,19,20} have shown the rich phenomenology that exists within non-equilibrium condensates. Polaritons are confined to two dimensions and the reduced dimensionality introduces an additional element of interest for the topological ordering mechanism leading to condensation, as recently evidenced in ref. 21. However, until now, such phenomena have mainly been observed in microcavities embedding quantum wells of III–V or II–VI semiconductors. As a result, experiments must be performed at low temperatures (below ∼ 20 K), beyond which excitons autoionize. This is a consequence of the low binding energy typical of Wannier–Mott excitons. Frenkel excitons, which are characteristic of organic semiconductors, possess large binding energies that readily allow for strong light–matter coupling and the formation of polaritons at room temperature. Remarkably, in spite of weaker interactions as compared to inorganic polaritons²², condensation and the spontaneous formation of vortices have also been observed in organic microcavities^23,24,25. However, the small polariton–polariton interaction constants, structural inhomogeneity and short lifetimes in these structures have until now prevented the observation of behaviour directly related to the quantum fluid dynamics (such as superfluidity). In this work, we show that superfluidity can indeed be achieved at room temperature and this is, in part, a result of the much larger polariton densities attainable in organic microcavities, which compensate for their weaker nonlinearities.

Our sample consists of an optical microcavity composed of two dielectric mirrors surrounding a thin film of 2,7-Bis[9,9-di(4-methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl)fluorene (TDAF) organic molecules. Light–matter interaction in this system is so strong that it leads to the formation of hybrid light–matter modes (polaritons), with a Rabi energy 2 Ω_R ∼ 0.6 eV. A similar structure has been used previously to demonstrate polariton condensation under high-energy non-resonant excitation²⁴. Upon resonant excitation, it allows for the injection and flow of polaritons with a well-defined density, polarization and group velocity.

Continue reading “Room-temperature superfluidity in a polariton condensate Physics” »