visual
visual

세미나

  • HOME
  • >
  • 소식
  • >
  • 세미나
날짜 2024-04-11 16:00 
일시 Apr 11(Thu), 16:00 
장소 E6-2, Rm#1323 
연사 Nanse Esaki (University of Tokyo) 
Nanse Esaki (Ph.D. student in Physics, The University of Tokyo)를 모시고 'Theoretical Studies of the Electric Field Induced Thermal Hall Effect in the Quantum Dimer Magnets XCuCl3 (X = Tl, K)' 주제에 대한 세미나를 개최하고자 합니다. 
물리학과 구성원 여러분들의 많은 참여 부탁드립니다.
 
1) Time : at 16:00 on Apr 11, 2024
2) Venue : E6-2, Rm#1323
3) Speaker : Nanse Esaki (Ph.D. student in Physics, The University of Tokyo)
4) Talk Title : Theoretical Studies of the Electric Field Induced Thermal Hall Effect in the Quantum Dimer Magnets XCuCl3 (X = Tl, K)
5) Abstract
   The thermal Hall effect in magnets has attracted increasing attention in recent years since it is a powerful probe of elementary excitations in solids and their nontrivial band topology. In quantum dimer magnets, where neighboring two = 1/2 spins form a dimer by the strong antiferromagnetic interaction, their elementary excitations are bosonic quasiparticle triplons. However, the thermal Hall effect of triplons has yet to be detected [1] although its candidate material has been proposed theoretically [2]. For this reason, we should seek other candidate materials exhibiting the thermal Hall effect of triplons.

 In this talk, I will present the theory of the electric field induced thermal Hall effect of triplons in the quantum dimer magnets XCuCl3 (X = Tl, K), which exhibit ferroelectricity in the Bose-Einstein condensation phase of triplons [3]. The interplay between ferroelectricity and magnetism in these materials leads to the magnetoelectric effect, i.e., an electric field induced Dzyaloshinskii-Moriya (DM) interaction between spins on the same dimer. In the high magnetic field regimes of the BEC phase where the lowest two modes are most relevant, we first consider the low-energy effective model [4] and find that there exist nodal lines in the Brillouin zone in the presence of an effective PT symmetry. Due to the presence of this symmetry, the system does not show the thermal Hall effect. However, the electric field induced intra-dimer DM interaction breaks the symmetry and gives rise to the thermal Hall effect. We also show that the magnitude (the direction) of the thermal Hall current can be well controlled by changing the strength (the direction) of the electric field.

 Additionally, we investigate the thermal Hall effect in lower magnetic field regimes of the BEC phase, considering all triplon modes. We identify that nodal lines protected by symmetries still exist without an electric field, although the effective PT symmetry does not. Interestingly, the thermal Hall effect in the lower magnetic field regimes can also be well controlled by an electric field, similar to the effective model for high magnetic field regimes.

 We anticipate that the thermal Hall effect in XCuCl3 can be detected in experiments with achievable electric and magnetic fields. Moreover, in the lower magnetic field regimes, we discover that an electric field can induce Weyl triplons, leading to multiple topological phase transitions by tuning a magnetic field with a finite electric field.

 

References
[1] S. Suetsugu et al., Phys. Rev. B 105, 024415 (2022).

[2] J. Romhányi, K. Penc, and R. Ganesh, Nat. Commun. 6, 6805 (2015).

[3] S. Kimura et al., Nat. Commun. 7, 12822 (2016).

[4] N. Esaki, Y. Akagi, and H. Katsura, arXiv: 2309.12812.

번호 날짜 장소 제목
223 2024-03-27 16:00  E6-2, #2502  [High Energy Theory Seminar] The Callan Rubakov Effect
222 2023-09-26 16:00  E6-2, #2502  [High Energy Theory Seminar]A new step in interacting dark sector cosmologies
221 2023-06-14 16:00  E6-2, #2502  [High-Energy Theory Seminar]Vertex algebras and extended operators in 4d N=2 SCFTs
220 2024-01-16 16:00  E6-2, #2502  [High Energy Theory Seminar] Towards quantum black hole microstates
219 2023-06-16 13:00  E6-2, #2502  Quantum critical states under extreme conditions
218 2023-11-01 16:00  E6-2, #2502  [High Energy Theory Seminar] Modular functions and 3D N=4 rank-zero superconformal field theories
217 2023-08-29 16:00  E6-2, #2502  [High Energy Theory Seminar] Towards string loop corrections in Calabi-Yau orientifold compactifications.
216 2023-06-01 16:00  E6-2, #5301  Hall viscosity and topological phenomena
215 2023-11-22 10:00  E6-2, #5301 & zoom  [High Energy Theory Seminar] Exact Quantum Algorithms to Recognize Quantum Phases of Matter
214 2020-02-12 13:00  E6-2, #5318  From inflation to new weak-scale file
213 2015-11-06 16:30  E6-2, #5318  Topological Dirac line nodes in centrosymmetric semimetals
212 2015-10-23 15:00  E6-2, #5318  Development of a Rogowski Coil as a new beam position monitor
211 2015-07-16 16:00  E6-2, 1318  Next-generation ultrafast laser technology for nonlinear optics and strong-field physics
210 2015-07-16 16:00  E6-2, 1501  KAIST Physics Distinguished Lecture
209 2016-03-11 13:30  E6-2, 1501 외  Physics Seminar Serises : 2016 Spring file
208 2019-07-03 15:00  E6-2, 2501  Many-body quantum electrodynamis (QED) with atoms and photons: A new platform for quantum optics" file
207 2018-06-14 10:00  E6-2, 2nd fl. #2502  Phonons and polariton-like particles in trapped ions for quantum computation and quantum simulation file
206 2015-10-16 15:00  E6-2, 5th fl. #5318  High Magnetic Fields to Probe the sub-eV range of Particle/Astroparticle Physics - From the OSQAR experiments at CERN up to new perspectives at LNCMI-Grenoble
205 2015-10-15 10:00  E6-2, 5th fl. #5318  Development of Large-Bore, High Field Magnets at the NHMFL
204 2017-12-15 09:20  E6-2, Lecture Room #1323  Workshop on Magnetism in Unconventional Superconductors 개최 file