Nonlinear optical control of chiral charge pumping in a topological Weyl semimetal
| Autor: | Jacob C. König-Otto, H. Dennis Drew, Martin Mittendorff, Alexander L. Gaeta, Ni Ni, Bing Shen, Mohammad M. Jadidi, Yigit Aytac, Thomas E. Murphy, Stephan Winnerl, Mehdi Kargarian |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Chiral anomaly High Energy Physics::Lattice Relaxation (NMR) Physics::Optics Weyl semimetal 02 engineering and technology Physik (inkl. Astronomie) 021001 nanoscience & nanotechnology Topology 01 natural sciences Semimetal Wyle semimetal Magnetic field TaAs chiral charge pumpping 0103 physical sciences 010306 general physics 0210 nano-technology Quantum Excitation Topological quantum number |
| Zdroj: | Physical Review B 102(2020), 245123 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.102.245123 |
| Popis: | Solids with topologically robust electronic states exhibit unusual electronic and optical properties that do not exist in other materials. A particularly interesting example is chiral charge pumping, the so-called chiral anomaly, in recently discovered topological Weyl semimetals, where simultaneous application of parallel DC electric and magnetic fields creates an imbalance in the number of carriers of opposite topological charge (chirality). Here, using time-resolved terahertz measurements on the Weyl semimetal TaAs in a magnetic field, we optically interrogate the chiral anomaly by dynamically pumping the chiral charges and monitoring their subsequent relaxation of the nonequilibrium state. Theory based on Boltzmann transport shows that the observed effects originate from an optical nonlinearity in the chiral charge pumping process. Our measurements reveal that the nonequilibrium chiral excitation relaxation time is much greater than 1 ns. The observation of terahertz-controlled chiral carriers with long coherence times and topological protection suggests the application of Weyl semimetals for quantum optoelectronic technology. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|