Despite the hype, it’s been surprisingly challenging to find quantum algorithms that outperform classical ones. In this episode, Ewin Tang discusses her pioneering work in “dequantizing” quantum algorithms — and what it means for the future of quantum computing.
The frequency regime lying in the shortwave infrared (SWIR) has very unique properties that make it ideal for several applications, such as being less affected by atmospheric scattering as well as being “eye-safe.” These include Light Detection and Ranging (LIDAR), a method for determining ranges and distances using lasers, space localization and mapping, adverse weather imaging for surveillance and automotive safety, environmental monitoring, and many others.
However, SWIR light is currently confined to niche areas, like scientific instrumentation and military use, mainly because SWIR photodetectors rely on expensive and difficult-to-manufacture materials. In the past few years, colloidal quantum dots —solution-processed semiconducting nanocrystals—have emerged as an alternative for mainstream consumer electronics.
While toxic heavy-metals (like lead or mercury) have typically been used, quantum dots can also be made with environmentally friendly materials such as silver telluride (Ag2Te). In fact, silver telluride colloidal quantum dots show device performance comparable to their toxic counterparts. But they are still in their infancy, and several challenges must be addressed before they can be used in practical applications.
A team of physicists have discovered a new approach that redefines the conception of a black hole by mapping out their detailed structure, as shown in a research study recently published in Journal of High Energy Physics.
The study details new theoretical structures called “supermazes” that offer a more universal picture of black holes to the field of theoretical physics. Based in string theory, supermazes are pivotal to understanding the structure of black holes on a microscopic level.
“General relativity is a powerful theory for describing the large-scale structure of black holes, but it is a very, very blunt instrument for describing black-hole microstructure,” said Nicholas Warner, co-author of the study and professor of physics, astronomy and mathematics at the USC Dornsife College of Letters, Arts and Sciences. In a framework of theories extending beyond Einstein’s equations, supermazes provide a detailed portrait of the microscopic structure of brane black holes.
Research by physicists at The City College of New York is being credited for a novel discovery regarding the interaction of electronic excitations via spin waves. The finding by the Laboratory for Nano and Micro Photonics (LaNMP) team headed by physicist Vinod Menon could open the door to future technologies and advanced applications such as optical modulators, all-optical logic gates, and quantum transducers. The work is reported in the journal Nature Materials.
The researchers showed the emergence of interaction between electronic excitations (excitons—electron hole pairs) mediated via spin waves in atomically thin (2D) magnets. They demonstrated that the excitons can interact indirectly through magnons (spin waves), which are like ripples or waves in the 2D material’s magnetic structure.
“Think of magnons as tiny flip-flops of atomic magnets inside the crystal. One exciton changes the local magnetism, and that change then influences another exciton nearby. It’s like two floating objects pulling toward each other by disturbing water waves around them,” said Menon.
An invention from Twente improves the quality of light particles (photons) to such an extent that building quantum computers based on light becomes cheaper and more practical. The researchers published their research in the journal Physical Review Applied.
Quantum computers are at a tipping point: tech giants and governments are investing billions, but there are two fundamental obstacles: the quantity of qubits and the quality of these qubits. UT researchers have invented a component for a photonic quantum computer that exchanges quantity for quality, and have shown that this exchange yields more computing power.
“Our discovery brings a future with powerful quantum computers a lot closer. That means improved medicines, new materials and safer communications. But also applications that we cannot yet imagine today,” says lead researcher Jelmer Renema. “This technology is an essential part of any future photonic quantum computer.”
Our understanding of layered quantum materials is still in its early stages. This is highlighted by new research from the Paul Scherrer Institute (PSI). Using advanced X-ray spectroscopy techniques at the Swiss Light Source (SLS
NASA’s Space Launch System (SLS) will be the most powerful rocket they’ve ever built. As part of NASA’s deep space exploration plans, it will launch astronauts on missions to an asteroid and eventually to Mars. As the SLS evolves, the launch vehicle will to be upgraded with more powerful versions. Eventually, the SLS will have the lift capability of 130 metric tons, opening new possibilities for missions to places like Saturn and Jupiter.
Big data has gotten too big. Now, a research team with statisticians from Cornell has developed a data representation method inspired by quantum mechanics that handles large data sets more efficiently than traditional methods by simplifying them and filtering out noise.
This method could spur innovation in data-rich but statistically intimidating fields, like health care and epigenetics, where traditional data methods have thus far proved insufficient.
The paper is published in the journal Scientific Reports.
“No two ways about it,” Altepeter told Breaking Defense today. “The number of companies that we’re announcing is a surprise to me. I did not expect we would get this many.”
For the winning teams, the value of QBI is not just the money. Indeed, first-round grants like those being announced today have typically been under $1 million — small change not just for the Pentagon but for tech firms and venture capitalists already investing billions into quantum ventures. We suggested everybody apply for a million, [but] some people came in and said they were going to do it for less, Altepeter said.
The unique value of a QBI award is that it gives the winning companies access to a DARPA-led team of quantum experts, pulled from both US government labs, including the famous Los Alamos, and federally funded research institutions. Their job is to act as independent testers, fresh eyes, and devil’s advocates, rigorously scrutinizing each participant’s quantum strategy.
Discovering and controlling exotic physical states is key in condensed matter physics and materials science. It has the potential to drive advancements in quantum computing and spintronics.
While studying a ferrimagnet model, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory uncovered a new phase of matter called “half-ice, half-fire.” This state is a twin to the “half-fire, half-ice” phase discovered in 2016.
Posted in computing, particle physics, quantum physics | Leave a Comment on Scientists unveil new way to electrically control spin for ultra-compact devices using altermagnetic quantum materials
Spintronics, an emerging field of technology, exploits the spin of electrons rather than their charge to process and store information. Spintronics could lead to faster, more power-efficient computers and memory devices. However, most spintronic systems require magnetic fields to control spin, which is challenging in ultracompact device integration due to unwanted interference between components. This new research provides a way to overcome this limitation.
As published in Materials Horizons, a research team led by the Singapore University of Technology and Design (SUTD) has introduced a novel method to control electron spin using only an electric field. This could pave the way for the future development of ultra-compact, energy-efficient spintronic devices.
Their findings demonstrate how an emerging type of magnetic material, an altermagnetic bilayer, can host a novel mechanism called layer-spin locking, thus enabling all-electrical manipulation of spin currents at room temperature.