Discover Top Posts Tagged with #mott insulators

An Australian-led study has found unusual insulating behavior in a new atomically-thin material—and the ability to switch it on and off.

An Australian-led study has found unusual insulating behavior in a new atomically-thin material—and the ability to switch it on and off. Materials that feature strong interactions between electrons can display unusual properties such as the ability to act as insulators even when they are expected to conduct electricity. These insulators, known as Mott insulators, occur when electrons become frozen because of strong repulsion they feel from other electrons nearby, preventing them from carrying a current.

#Science #Chemistry #Materials Science #Physics #Mott Insulators #Electrons

Topological defects can trigger a transformation from insulating to conductive behavior in Mott materials

Researchers at Università Cattolica, Brescia campus, have discovered that the transition from insulating to conductive behavior in certain materials is driven by topological defects in the structure. Specifically, a study published in Nature Communications shows that so-called "Mott materials"—a type of insulator fundamentally different from conventional insulators, capable of switching from an insulating to a conductive state (a process known as "resistive switching")—can change state precisely due to topological defects in their crystal structure. This study, conducted specifically on a particular vanadium oxide (V₂O₃), reveals that these defects trigger this transition. The study was coordinated by Professor Claudio Giannetti, director of the Interdisciplinary Laboratories of Advanced Material Physics in the Department of Mathematics and Physics at the university. The study was carried out in collaboration with IMDEA Nanociencia, KU Leuven, SISSA, and Diamond Light Source.

Spontaneous supercrystal discovered in switching metal-insulator

A supercrystal formation previously unobserved in a metal-insulating material was discovered by a Cornell-led research team, potentially unlocking new ways to engineer materials and devices with tunable electronic properties. The researchers showed that the atomic structure in the thin-film Mott insulator Ca2RuO4—part of a unique family of materials that can switch between being a metal and an insulator due to quantum effects—forms an anisotropic, organized pattern with multiple spatial periods below temperatures of 200 to 250-degrees Kelvin. The spontaneous supercrystal formation was detailed June 17 in the journal Advanced Materials. "This is a great example of complexity arising from simplicity," said Oleg Gorobtsov, postdoctoral fellow and lead author of the study.

Researchers find unexpected roadblock to conductivity in Mott insulators

In the realm of condensed matter physics, few phenomena captivate physicists' curiosity as much as Mott insulators. According to traditional theory, this odd class of materials should be capable of conducting electricity, yet they behave mostly as insulators. What's even more bizarre is that when electrons are added, the material can actually become a superconductor, conducting an electric current with zero resistance. However, it can also stay an insulator no matter how many electrons are added. The extreme opposite reactions have puzzled scientists for decades, but some of those mysteries may be coming to an end. Scientists from Brown University working with an international team of researchers have developed a novel theory, which they verified through a series of laboratory experiments, to fundamentally explain for the first time why one type of Mott insulator stubbornly resists conducting electricity even when electrons are added.

Researchers present new method to fine-tune properties of layered transition metal dichalcogenide crystals

A research group led by Prof. Cao Liang from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, together with collaborators, has introduced an additional translational degree of freedom in layered transition metal dichalcogenide crystals, enabling fine-tuning of their physical properties. The results were published in Nature Communications. Layered Mott insulators help us understand how different states such as Mott insulators, charge density waves, and superconductors are connected. By changing how these layers stack and behave under pressure and temperature, scientists can explore these relationships.

When does a conductor not conduct? Switching a 2D metal-organic framework from an insulator to a metal

An Australian-led study has found unusual insulating behavior in a new atomically-thin material—and the ability to switch it on and off. Materials that feature strong interactions between electrons can display unusual properties such as the ability to act as insulators even when they are expected to conduct electricity. These insulators, known as Mott insulators, occur when electrons become frozen because of strong repulsion they feel from other electrons nearby, preventing them from carrying a current. Led by FLEET at Monash University, a new study, published this week in Nature Communications, has demonstrated a Mott insulating phase within an atomically-thin metal-organic framework (MOF), and the ability to controllably switch this material from an insulator to a conductor. This material's ability to act as an efficient "switch" makes it a promising candidate for application in new electronic devices such as transistors.

New material design for transistors could downsize next-gen tech

By better taming the Jekyll-and-Hyde nature of an alternative to the semiconductor—one that transitions from electricity-resisting insulator to current-conducting metal—Nebraska's Xia Hong and colleagues may have unlocked a new path to smaller, more efficient digital devices. The team reports its findings in the journal Nature Communications. The semiconductor's ability to conduct electricity in the Goldilocks zone—poorer than a metal, better than an insulator—positioned it as the just-right choice for engineers looking to build transistors, the tiny on-off switches that encode the 1s and 0s of binary. Apply some voltage to the control knob known as a gate insulator, and the semiconductor channel allows electric current to flow (1); remove it, and that flow ceases (0). Millions of those nanoscopic, semiconductor-based transistors now coat modern microchips, switching on and off to collectively process or store data. But as minuscule as the transistors already are, the demands of consumers and competition continue pushing electrical engineers to shrink them even further, either for the sake of squeezing in more functionality or downsizing the devices that house them.

Surprise physics in insulating material offer path for faster tech

Researchers led by Cornell have discovered an unusual phenomenon in a metal-insulating material, providing valuable insights for the design of materials with new properties by way of faster switching between states of matter. Mott insulators are a family of materials with unique electronic properties, including ones that can be manipulated by stimuli such as light. The origin of the unique properties is not fully understood, partly due to the challenging task of imaging the material's nanostructures in real-space and capturing how these structures undergo phase changes in as fast as a trillionth of a second. A new study published in Nature Physics unraveled the physics of the Mott insulator, Ca2RuO4, as it was stimulated with a laser. In unprecedented detail, researchers observed interactions between the material's electrons and underlying lattice structure, using ultrafast X-ray pulses to capture "snapshots" of structural changes in the Ca2RuO4 within critical picoseconds after excitation with the laser.

#mott insulators

Trending Tags

Recently Viewed Tags

#mott insulators