Scientists at the US Department of Energy’s Ames Laboratory and collaborators at Brookhaven National Laboratory and the University of Alabama at Birmingham have discovered a new light-induced circuit breaker that twists the material’s crystal lattice, igniting a giant electron current that appears to be nearly without Discovery The discovery was made in a very promising category of topological materials for spintronics, topological effect transistors and quantum computing.
Weyl and Dirac semimetals can expect exotic, almost non-scattering, electron conduction properties that take advantage of the unique state in the crystal lattice and the electronic structure of the material that protects the electrons from such action. These anomalous electron transport channels, protected by symmetry and topology, do not normally occur in conventional metals such as copper. After decades of description only in the context of theoretical physics, there is a growing interest in fabricating, exploring, refining, and controlling their electronically protected electronic properties for device applications. For example, large-scale adoption of quantum computing requires the construction of equipment in which fragile quantum states are protected from impurities and noisy environments. One approach to achieving this is through the development of quantum topological calculation, in which cubits are based on non-distributed “symmetry-protected” electric currents that are immune to noise.
“Light-induced lattice winding, or a phonon switch, can control the symmetry of crystal inversion and giant photogeneration current with very little resistance,” said Jigang Wang, senior scientist at Ames Laboratory and professor of physics at State University. of Iowa. “This new principle of control does not require static electric or magnetic fields, and has much faster speeds and lower energy costs.”
“This discovery could extend to a new principle of quantum computing based on chiral physics and energy dispersion without distribution, which may have much faster speeds, lower energy costs and higher operating temperatures.” said Liang Luo, a scientist at the Ames Laboratory and the first author of the paper.
Wang, Luo and their colleagues achieved just that, using terahertz laser light spectroscopy (one trillion cycles per second) to examine and propel these materials into discovering the mechanisms by which symmetry changes their properties.
In this experiment, the team changed the symmetry of the electronic structure of the material, using laser pulses to twist the arrangement of the crystal lattice. This light switch enables “Weyl dots” in the material, causing the electrons to behave like immeasurable particles that can hold the shielded, low-distribution current required.
“We achieved this giant non-scattering current by directing periodic motions of atoms around their equilibrium position in order to break the symmetry of the inversion of the crystal,” says Ilias Perakis, professor of physics and chairs at the University of Alabama at Birmingham. “This principle of Weyl’s transport control and semi-metallic topology seems to be universal and will be very useful in the future development of quantum computing and electronics with high speed and low power consumption.”
“What we have been missing so far is a low energy and a fast transition to promote and control the symmetry of these materials,” said Qiang Li, head of the Brookhaven National Laboratory’s Advanced Energy Group. “Our discovery of a key of light symmetry opens up an interesting opportunity to carry electron current without scattering, a topologically protected state that does not weaken or slow down when it falls into material imperfections and impurities.”
Reference: “A phonon symmetry switch induced by light and a topological electric current without giant distribution in ZrTe5”By Liang Luo, Di Cheng, Boqun Song, Lin-Lin Wang, Chirag Vaswani, Prime Minister Lozano, G. Gu, Chuankun Huang, Richard HJ Kim, Zhaoyu Liu, Joong-Mok Park, Yongxin Yao, Kaiming Ho, Ilias E. Perakis, Qiang Li and Jigang Wang, January 18, 2021, Natural materials.
DOI: 10.1038 / s41563-020-00882-4
Terahertz photocursion and laser spectroscopy experiments and model construction were performed at Ames Laboratory. Sample development and magneto-transport measurements were performed by the Brookhaven National Laboratory. Data analysis was performed by the University of Alabama at Birmingham. The first principle calculations and topological analysis were performed by the Center for the Advancement of Topological Semitones, an Energy Boundary Research Center funded by the DOE Office of Science.