A new material discovered through research from the MIT Plasma Science and Fusion Center promises to create the first strain-tunable materials — materials that adjust their electronic properties accor.
Category: quantum physics – Page 454
When electrons slowly vanish during cooling: Researchers observe an effect unique to the quantum world
Many substances change their properties when they are cooled below a certain critical temperature. Such a phase transition occurs, for example, when water freezes. However, in certain metals there are phase transitions that do not exist in the macrocosm. They arise because of the special laws of quantum mechanics that apply in the realm of nature’s smallest building blocks.
It is thought that the concept of electrons as carriers of quantized electric charge no longer applies near these exotic phase transitions. Researchers at the University of Bonn and ETH Zurich have now found a way to prove this directly. Their findings allow new insights into the exotic world of quantum physics. The publication has now been released in the journal Nature Physics.
If you cool water below zero degrees Celsius, it solidifies into ice. In the process, it abruptly changes its properties. As ice, for example, it has a much lower density than in a liquid state—which is why icebergs float. In physics, this is referred to as a phase transition.
Research team synchronizes single photons using an atomic quantum memory
A long-standing challenge in the field of quantum physics is the efficient synchronization of individual and independently generated photons (i.e., light particles). Realizing this would have crucial implications for quantum information processing that relies on interactions between multiple photons.
Researchers at Weizmann Institute of Science recently demonstrated the synchronization of single, independently generated photons using an atomic quantum memory operating at room-temperature. Their paper, published in Physical Review Letters, could open new avenues for the study of multi-photon states and their use in quantum information processing.
“The project idea came about several years ago, when our group and the group of Ian Walmsley demonstrated an atomic quantum memory with an inverted atomic-level scheme compared to the typical memories—the ladder memory, named fast ladder memory (FLAME),” Omri Davidson, one of the researchers who carried out the study, told Phys.org. “These memories are fast and noise-free, and therefore they are useful for synchronization of single photons.”
Novel Raman technique breaks through 50 years of frustration
Raman spectroscopy—a chemical analysis method that shines monochromatic light onto a sample and records the scattered light that emerges—has caused frustration among biomedical researchers for more than half a century. Due to the heat generated by the light, live proteins are nearly destroyed during the optical measurements, leading to diminishing and non-reproducible results. As of recently, however, those frustrations may now be a thing of the past.
A group of researchers with the Institute for Quantum Sciences and Engineering at Texas A&M University and the Texas A&M Engineering Experiment Station (TEES) have developed a new technique that allows low-concentration and low-dose screenings of protein-to-ligand interactions in physiologically relevant conditions.
Titled thermostable-Raman-interaction-profiling (TRIP), this new approach is a paradigm-shifting answer to a long-standing problem that provides label-free, highly reproducible Raman spectroscopy measurements. The researchers published their findings in the Proceedings of the National Academy of Sciences.
Team creates simple superconducting device that could dramatically cut energy use in computing
MIT scientists and colleagues have created a simple superconducting device that could transfer current through electronic devices much more efficiently than is possible today. As a result, the new diode, a kind of switch, could dramatically cut the amount of energy used in high-power computing systems, a major problem that is estimated to become much worse.
Even though it is in the early stages of development, the diode is more than twice as efficient as similar ones reported by others. It could even be integral to emerging quantum computing technologies. The work, which is reported in the July 13 online issue of Physical Review Letters, is also the subject of a news story in Physics Magazine.
“This paper showcases that the superconducting diode is an entirely solved problem from an engineering perspective,” says Philip Moll, Director of the Max Planck Institute for the Structure and Dynamics of Matter in Germany. Moll was not involved in the work. “The beauty of [this] work is that [Moodera and colleagues] obtained record efficiencies without even trying [and] their structures are far from optimized yet.”
The Quantum Odyssey: Visualizing Topological Materials With “3D Glasses”
An international team of scientists has succeeded in experimentally confirming a characteristic of topological materials.
Scientists from around the globe have experimentally confirmed a unique characteristic of topological materials. Using ‘3D glasses’-like technology and particle accelerators, they successfully visualized the relationship between an electron’s topology and its quantum mechanical properties, marking a significant step forward in understanding these future-focused materials.
Topological quantum materials are seen as a beacon of hope for energy-saving electronics and the high-tech of the future. A defining feature of these materials is their ability to conduct spin-polarized electrons on their surface, while remaining non-conductive inside. To put this into perspective: In spin-polarized electrons, the intrinsic angular momentum, i.e. the direction of rotation of the particles (spin), is not purely randomly aligned.
Two Atoms Vibrate Like a Laser
A laser for vibrational energy, rather than for light, operating in the quantum regime could teach researchers about the interplay between spin, vibration, and dissipation in quantum mechanics.
Phonon lasers replace the light excitations (photons) that are used in a standard laser with vibrational excitations of matter (phonons). Researchers have now coaxed two ions into forming a phonon laser containing fewer than 10 phonons, placing it firmly in the quantum regime [1], whereas previous phonon lasers had at least 10,000 phonons. The researchers plan to use this quantum phonon laser as a tool to investigate the role of dissipation in the behavior of quantum systems.
Dissipation—energy leaking into or out of a system in the form of heat—is often seen as a nuisance in physics, for example, when it takes the form of air resistance and reduces the fuel efficiency of a car or an airplane. But quantum systems also exhibit dissipation, and its effects in the quantum realm are not fully understood. Jonathan Home of the Swiss Federal Institute of Technology (ETH) in Zurich and his colleagues wanted to investigate how two separate sources of dissipation can interact to affect the behavior of a quantum system. “A laser is the simplest quantum system we could think of” that allows such experiments, Home says.