Computer Simulations Show How Light Pulses Can Create Channels that Conduct Electricity with No Resistance in Atomically Thin Semiconductors
Theoretical physicists at the Department of Energy’s SLAC National Accelerator Laboratory used computer simulations to show how special light pulses could create robust channels where electricity flows without resistance in an atomically thin semiconductor.
If this approach is confirmed by experiments, it could open the door to a new way of creating and controlling this desirable property in a wider range of materials than is possible today.
The result was published in Nature Communications.
Over the past decade, understanding how to create this exotic type of material – known as “topologically protected” because its surface states are impervious to minor distortions – has been a hot research topic in materials science. The best-known examples are topological insulators, which conduct electricity with no resistance in confined channels along their edges or surfaces, but not through their interiors.
SLAC and Stanford University researchers have been at the forefront of discovering such materials and investigating their properties, which could have future applications in microelectronic circuits and devices. This year’s Nobel Prize in Physics was awarded to three scientists who first suggested the possibility of topologically protected material properties.
Previous theoretical studies had looked at how light might induce topologically protected phenomena in graphene, a sheet of pure carbon just one atom thick. Unfortunately, it would take an impractically high light energy and intensity to induce that effect in graphene. In this study, SLAC researchers focused on tungsten disulfide and related compounds, which form sheets just one molecule thick and are intrinsically semiconducting
The researchers simulated experiments in which pulses of circularly polarized light, in the red to near-infrared wavelength range, hit a single layer of tungsten disulfide. The results showed that during the time the material was illuminated, its electrons organized themselves in a manner fundamentally different from graphene, creating new paths with absolutely no electrical resistance along the sample’s edges.
To account for the fluctuating interactions between light waves and electrons, the researchers employed a periodically time-varying frame of reference that had roots dating back to the 1880s and French mathematician Gaston Floquet. The approach clearly showed that lower-energy light, to which the material would seem transparent, would create topologically protected, no-resistance edge paths in the tungsten disulfide monolayer.
Moreover, the simulation showed that unwanted heating of the material that would disrupt the paths could be avoided by tuning the light energy to be slightly less than the most-efficient “resonant” energy.
“We are the first to connect first-principles material models with light-induced topologically protected states while mitigating excess material heating,” said Martin Claassen, a Stanford graduate student working at SLAC and lead author of the technical paper.
The researchers are in discussions with other research groups that could lead to experiments that test their theoretical predictions in real materials.
Learn more: SLAC Study: Light Can Switch On Topological Materials
[osd_subscribe categories=’topological-materials’ placeholder=’Email Address’ button_text=’Subscribe Now for any new posts on the topic “TOPOLOGICAL MATERIALS”‘]
Receive an email update when we add a new TOPOLOGICAL MATERIALS article.
The Latest on: Topological materials
[google_news title=”” keyword=”topological materials” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Topological materials
- MIT Teams Secure NSF Grants for Sustainable Materials Researchon April 24, 2024 at 5:28 pm
Two teams led by MIT researchers were selected in December 2023 by the U.S. National Science Foundation (NSF) Convergence Accelerator, a part of the TIP Directorate, to receive awards of $5 million ...
- Researchers discover dual topological phases in an intrinsic monolayer crystalon April 17, 2024 at 10:08 am
An international team working with single-atom thick crystals found TaIrTe4's transition between the two distinct topological states of insulation and conduction. The material exhibited zero ...
- Beyond Theory: Dual Topological Insulating States Found in Monolayer Materialon April 10, 2024 at 10:14 pm
Scientists at Boston College have identified a material known as a dual quantum spin Hall insulator, which offers a promising foundation for investigating exotic quantum phases and electromagnetism. A ...
- Novel Quantum Effect Observed in a Crystalline Materialon April 10, 2024 at 5:00 pm
These have been observed in previous experiments, but never simultaneously in the same material where they mix to form a new state of matter. In recent years, the study of topological states of matter ...
- Physicists discover a novel quantum state in an elemental solidon April 10, 2024 at 8:44 am
For more than a decade, scientists have used bismuth (Bi)-based topological insulators to demonstrate and explore exotic quantum effects in bulk solids mostly by manufacturing compound materials, like ...
- Physicists discover a novel quantum state in an elemental solidon April 9, 2024 at 5:00 pm
The experiment Bismuth-based materials are capable, at least in principle, of hosting a topological state of matter at high temperatures. However, these require complex materials preparation under ...
- New Topological Metamaterial Amplifies Sound Waves Exponentiallyon March 27, 2024 at 5:01 pm
This metamaterial is the first instance of a so-called ‘bosonic Kitaev chain’, which gets its special properties from its nature as a topological material. It was realized by making nanomechanical ...
- New topological metamaterial amplifies sound waves exponentiallyon March 27, 2024 at 9:14 am
Researchers at AMOLF, in collaboration with partners from Germany, Switzerland, and Austria, have realized a new type of metamaterial through which sound waves flow in an unprecedented fashion.
- New topological metamaterial amplifies sound waves exponentiallyon March 27, 2024 at 9:02 am
This metamaterial is the first instance of a so-called ‘bosonic Kitaev chain’, which gets its special properties from its nature as a topological material. It was realized by making ...
via Bing News