Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: quantum physics – Page 812

Ultracold atoms put high-temperature superconductors under the microscope

Physicists use a Bose-Einstein condensate to study phase transitions in an iron pnictide superconductor.

Physicists have deployed a Bose-Einstein condensate (BEC) as a “quantum microscope” to study phase transitions in a high-temperature superconductor. The experiment marks the first time a BEC has been used to probe such a complicated condensed-matter phenomenon, and the results – a solution to a puzzle involving transition temperatures in iron pnictide superconductors – suggest that the technique could help untangle the complex factors that enhance and inhibit high-temperature superconductivity.

A BEC is a state of matter that forms when a gas of bosons (particles with integer quantum spin) is cooled to such low temperatures that all the bosons fall into the same quantum state. Under these conditions, the bosons are highly sensitive to tiny fluctuations in the local magnetic field, which perturb their collective wavefunction and create patches of greater and lesser density in the gas. These variations in density can then be detected using optical techniques.

The new instrument, known as a scanning quantum cryogenic atom microscope (SQCRAMscope), puts this magnetic field sensitivity to practical use. “Our SQCRAMscope is basically like a microscope – a big lens, focusing light down on a sample, looking at the reflected light – except right at the focus we have a collection of quantum atoms that transduces the magnetic field into a light field,” explains team leader Benjamin Lev, a physicist at Stanford University in the US. “It’s a quantum gas transducer.”

Direct Visualization of Quantum Dots Reveals Shape of Quantum Wave Function of the Trapped Electrons

Researchers used a scanning tunneling microscope to visualize quantum dots in bilayer graphene, an important step toward quantum information technologies.

Trapping and controlling electrons in bilayer graphene quantum dots yields a promising platform for quantum information technologies. Researchers at UC Santa Cruz have now achieved the first direct visualization of quantum dots in bilayer graphene, revealing the shape of the quantum wave function of the trapped electrons.

The results, published on November 23, 2020, in Nano Letters, provide important fundamental knowledge needed to develop quantum information technologies based on bilayer graphene quantum dots.

Quantum X-ray microscope “ghost images” molecules using entanglement

Engineers at Brookhaven National Laboratory have designed a strange new X-ray microscope that takes advantage of the spooky world of quantum physics to “ghost image” biomolecules in high resolution but at a lower radiation dose.

X-ray microscopes are useful tools for imaging samples in high resolution, but the radiation involved can damage sensitive samples such as viruses, bacteria and some cells. Reducing the radiation dose is one way around that problem, but unfortunately that also reduces the resolution of the image.

Now, the Brookhaven team has found a way to maintain higher resolution with a lower radiation dose – and all they had to do was tap into the quirks of quantum physics that boggled minds like Einstein’s.

Upcoming Video Game Will Generate New Levels Using Qiskit and a Quantum Simulator

By Christopher Sciacca

The first video games debuted in the1950s, later reaching mainstream popularity in the 1970s and 80s with arcades and home video systems like Atari and Commodore 64. Remember SpaceWar! and Pong? While limited by the capabilities of the hardware, they laid the foundation for the games we develop and play today, which by 2025 is expected to be a whopping $256 billion industry.

This history and the importance of these early video games was not lost on Qiskit’s James Wootton. In 2017, he created the world’s first video game for a quantum computer, Cat-Box-Scissors, based on Rock-Paper-Scissors. He continued creating other quantum games, in the process attracting quantum enthusiasts and video game developers who wanted to try something new. And soon, games incorporating quantum computing concepts will be available for anyone to play.

This Weird, Cheap Quantum Device Can Run For a Year With a Single Kick of Energy

As our need for electronic gadgets and sensors grows, scientists are coming up with new ways to keep devices powered for longer on less energy.

The latest sensor to be invented in the lab can go for a whole year on a single burst of energy, aided by a physics phenomenon known as quantum tunnelling.

The tunnelling aspect means that with the help of a 50-million-electron jumpstart, this simple and inexpensive device (made up of just four capacitors and two transistors) can keep going for an extended period of time.

Cracking the secrets of an emerging branch of physics

This discovery opens the door to topological quantum computing. Current quantum computing systems, where the elemental units of calculation are qubits that perform superfast calculations, require superconducting materials that only function in extremely cold conditions. Fluctuations in heat can throw one of these systems out of whack.

“The properties inherent to materials such as TaP could form the basis of future qubits,” says Nguyen. He envisions synthesizing TaP and other topological semimetals — a process involving the delicate cultivation of these crystalline structures — and then characterizing their structural and excitational properties with the help of neutron and X-ray beam technology, which probe these materials at the atomic level. This would enable him to identify and deploy the right materials for specific applications.

“My goal is to create programmable artificial structured topological materials, which can directly be applied as a quantum computer,” says Nguyen. “With infinitely better heat management, these quantum computing systems and devices could prove to be incredibly energy efficient.”

The Physics of COVID-19 –“People are Like Galaxies”

Some of the greatest medical discoveries of the 20th century came from physicists who switched careers and became biologists. Francis Crick, who won the 1962 Nobel Prize in Physiology and helped identify the structure of DNA, started his career as a physicist, as did Leo Szilard who conceived the nuclear chain reaction in 1933, writing the letter for Albert Einstein’s signature that resulted in the Manhattan Project that built the atomic bomb, but spent the last decades of his life doing pioneering work in biology, including the first cloning of a human cell.

Today, a group of world-renowned researchers at the Perimeter Institute for Theoretical Physics with expertise from cosmology to quantum gravity are using physics to help fight the COVID-19 pandemic.

/* */