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
373 2022-12-20 16:00  E6-2. #2501  Getting into Biology and Medicine as Physicist
372 2016-10-07 16:00  E6-2. #1323(1st fl.)  “Tilt engineering of 4d and 5d transition metal oxides?”
371 2016-05-11 16:00  E6-2. #1323(1st fl.)  The quest for novel high-temperature superconductors---Prospects and progress in iridates
370 2016-11-10 16:00  E6-2. #1323(1st fl.)  Low Dimensional Active Plasmonics and Electron Optics in Graphene
369 2016-11-04 13:30  E6-2. #1323(1st fl.)  Exotic phenomena at oxide LaAlO3/SrTiO3 hetero-interface and their applications
368 2016-05-24 16:00  E6-2. #1323(1st fl.)  Electronic and magnetic properties of 2D transition-metal thiophosphates and tunability of magnetic order with carrier density
367 2016-11-04 15:00  E6-2. #1323(1st fl.)  Quantum information experiments using few electron spins in semiconductors
366 2016-10-07 13:30  E6-2. #1323(1st fl.)  “Symmetry and topology in transition metal dichalcogenide?”
365 2022-05-12 16:00  E6-2. #1323 & Zoom  New frontiers of electroweak physics at the LHC
364 2022-05-18 16:00  E6-2. #1323 & Zoom  Geometry, Algebra, and Quantum Field Theory
363 2022-05-19 16:00  E6-2. #1323 & Zoom  Chasing Long Standing Neutrino Anomalies with MicroBooNE
362 2022-05-11 16:00  E6-2. #1323 & Zoom  Gravity as a phenomenon in quantum dynamics
361 2023-06-22 16:00  E6-2,1323  [High Energy Physics Seminar] The Branes Behind Generalized Symmetry Operators
360 2015-07-15 14:00  E6-2,1323  Electronic and optical properties of titanate-based oxide superlattices
359 2019-12-27 15:00  E6-2,#5318  The superconducting order parameter puzzle of Sr2RuO4 file
358 2023-11-08 10:00  E6-2,#2502 & zoom  [High Energy Theory seminar] The Vacuum Sector of Asymptotically Isometric Codes
357 2019-07-21 12:00  E6-2,# 5318  Challenges and Opportunities in Theoretical Particle Physics 2019 file
356 2023-10-11 16:00  E6-2, Rm2502  [High Energy Theory Seminar] Axion Magnetic Resonance
355 2023-12-08 10:30  E6-2, Rm#2502  Novel transport phenomena in insulators
» 2024-04-11 16:00  E6-2, Rm#1323  Theoretical Studies of the Electric Field Induced Thermal Hall Effect in the Quantum Dimer Magnets XCuCl3 (X = Tl, K)