Quantum Hall effect and the third dimension
2021-06-02
(Press-News.org) The quantum Hall effect traditionally only plays a role in two-dimensional electron systems. Recently, however, a three-dimensional version of the quantum Hall effect was described in the Dirac semimetal ZrTe5. It has been suggested that this version results from a magnetic field-induced Fermi surface instability that transforms the original three-dimensional electron system into a stack of two-dimensional electron systems. Now scientists at the Max Planck Institute for Chemical Physics of Solids in Dresden, at the Technical University of Dresden, at the Brookhaven National Laboratory in New York, at the Helmholtz Center Dresden-Rossendorf, the Max Planck Institute for Microstructure Physics in Halle and at the Würzburg-Dresden Cluster of Excellence ct.qmat were able to show that the electron system of ZrTe5, contrary to the original explanation, remains three-dimensional even in strong magnetic fields and that the quasi-quantization of the Hall effect is nevertheless directly linked to quantum-Hall physics.
The findings from the study of quantum Hall physics in the third dimension can be universally applied to conventional metals and promise a unified explanation of the plateaus that have been observed in Hall measurements in many three-dimensional materials, which were often puzzling in the past. In addition, the concept can be directly applied to generalize the two-dimensional quantum anomalous Hall effect to generic three-dimensional magnets.
The results were published in Nature Communications.
INFORMATION:
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-06-02
Boulder, Colo., USA: GSA's dynamic online journal, Geosphere, posts articles online regularly. Locations and topics studied this month include the Moine thrust zone in northwestern Scotland; the Eastern California shear zone; implementation of "OpenTopography"; the finite evolution of "mole tracks"; the southern central Andes; the work of International Ocean Discovery Program (IODP) Expedition 351; and the Fairweather fault, Alaska, USA. You can find these articles at https://geosphere.geoscienceworld.org/content/early/recent.
Detrital-zircon analyses, provenance, and ...
2021-06-02
RIVERSIDE, Calif. -- As its name suggests, dark matter -- material which makes up about 85% of the mass in the universe -- emits no light, eluding easy detection. Its properties, too, remain fairly obscure.
Now, a theoretical particle physicist at the University of California, Riverside, and colleagues have published a research paper in the Journal of High Energy Physics that shows how theories positing the existence a new type of force could help explain dark matter's properties.
"We live in an ocean of dark matter, yet we know very little about what it could be," said Flip Tanedo, an assistant professor of physics and astronomy and the paper's senior author. "It is one of the most vexing known unknowns in nature. ...
2021-06-02
It's long been known that people living with HIV experience a loss of white matter in their brains. As opposed to "gray matter," which is composed of the cell bodies of neurons, white matter is made up of a fatty substance called myelin that coats neurons, offering protection and helping them transmit signals quickly and efficiently. A reduction in white matter is associated with motor and cognitive impairment.
Earlier work by a team from the University of Pennsylvania and Children's Hospital of Philadelphia (CHOP) found that antiretroviral therapy (ART)--the lifesaving suite ...
2021-06-02
There is a long-held belief that having your pet sleep on the bed is a bad idea. Aside from taking up space, noisy scratching, or triggering allergies, the most common assertion averred that your furry companion would disrupt your sleep.
A new study published in the journal Sleep Health tells a different story. Researchers at Concordia's Pediatric Public Health Psychology Lab (PPHP) found that the sleep quality of the surprisingly high number of children who share a bed with their pets is indistinguishable from those who sleep alone.
"Sleeping with your pet does not appear to be disruptive," ...
2021-06-02
Do firms respond to tougher competition by searching for completely new technological solutions (exploration), or do they work to defend their position by improving current technologies (exploitation)?
Competition from increased import penetration generally results in tight profit margins, low prices, and strong efficiency pressures, immediately affecting firms' bottom lines in the form of reduced profits and increased bankruptcy risk.
A firm's R&D strategy is one of the fundamental determinants of success or failure when responding to competitive threats. To ensure both short-term performance and long-term survival, firms have two basic R&D options: explore new knowledge or exploit existing knowledge bases. ...
2021-06-02
A new study by a team of University of Rochester psychologists and other researchers in the Collaborative Initiative on Fetal Alcohol Spectrum Disorders (CIFASD) finds that partners of mothers-to-be can directly influence a pregnant woman's likelihood of drinking alcohol and feeling depressed, which affects their babies' development.
The study, which appeared in Alcoholism: Clinical & Experimental Research, highlights the importance of engaging partners in intervention and prevention efforts to help pregnant women avoid drinking alcohol. A baby's prenatal alcohol ...
2021-06-02
Nano-sized particles have been engineered in a new way to improve detection of tumors within the body and in biopsy tissue, a research team in Sweden reports. The advance could enable identifying early stage tumors with lower doses of radiation.
In order to enhance visual contrast of living tissues, state-of-the-art imaging relies on agents such as fluorescent dyes and biomolecules. Advances in nanoparticle research have expanded the array of promising contrast agents for more targeted diagnostics, and now a research team from KTH Royal Institute of Technology has raised the bar further yet. They are combining optical and X-ray fluorescence contrast agents into a single enhancer for both modes.
Muhammet ...
2021-06-02
Researchers from Sinai Health have published a study providing an ultra-detailed look at the organization of a living human cell, providing a new tool that can help scientists around the world better understand what happens during disease.
The new study, out today in the journal END ...
2021-06-02
In the universe's earliest moments, particles existed in an unimaginably hot plasma, whose behaviour was governed by deeply complex webs of interaction between individual particles. Today, researchers can recreate these exotic conditions through high-energy collisions between heavy ions, whose products can tell us much about how hot, strongly-interacting matter behaves. Yet without extensive, highly coordinated collaborations between researchers across many different backgrounds, studies like this simply wouldn't be possible. This Topical Issue of EPJ A draws together a large collection of papers inspired by the theory of hot matter and relativistic heavy-ion collisions (THOR) European Cooperation ...
2021-06-02
The myriad processes occurring in biological cells may seem unbelievably complex at first glance. And yet, in principle, they are merely a logical succession of events, and could even be used to form digital circuits. Researchers have now developed a molecular switching circuit made of DNA, which can be used to mechanically alter gels, depending on the pH. DNA-based switching circuits could have applications in soft robotics, say the researchers in their article in Angewandte Chemie.
DNA is a long molecule that can be folded and twisted in various ways. It has a backbone and bases that stick out from the backbone and pair up with counterparts in other DNA strands. When a series of these matching pairs comes ...
LAST 30 PRESS RELEASES:
[Press-News.org] Quantum Hall effect and the third dimension
