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
389 2022-03-29 10:00  E6 #1501/zoom, E6 #2502/zoom  Non-reciprocal phase transitions file
388 2022-10-04 16:00  E6 #2501  Distinguishing 6d (1, 0) SCFTs
387 2022-04-14 16:00  E6 1323  (광학분야 특별세미나)Holographic tomography of dielectric tensors at optical frequency
386 2022-04-28 16:00  E6 1323  (광학분야 특별세미나)Adiabaticity and symmetry in optical waveguide design
385 2022-05-10 16:00  E6 1323  (광학분야 특별세미나)Testing quantum thermodynamics using quantum optics
384 2022-05-26 16:00  E6 1323  (광학분야 특별세미나)Topological photonic devices
383 2022-06-23 11:00  E6 Room(#1322)  JILA’s search for the electron’s Electric Dipole Moment (eEDM) to probe physics beyond the standard model file
382 2023-02-28 11:00  E6 Room(#1322)  Topotactic redox engineering toward novel material file
381 2018-11-22 15:00  E6 Room(#1323)  Experimental and Computational Study on Physical Properties based on Granular System file
380 2019-05-08 16:00  E6 Room(#1323)  Imaging valley dependent electron transport in 2D semiconductors file
379 2019-08-16 14:00  E6 Room(#1323)  Multiferroic and Magnetoelectric Effects by Tailoring Interfacial Chemistry and Physics in Correlated Oxides file
378 2019-08-01 14:00  E6 Room(#1323)  Low-density Superconductivity in SrTiO3 Probed by Planar Tunneling Spectroscopy file
377 2019-08-06 16:00  E6 Room(#1323)  Visualization of in-plane piezoresponse vector fields file
376 2022-05-25 14:00  E6 Room(#2501)  Atomic-level insights into ferroelectric switching and preferred orientation of ultrathin hafnia file
375 2019-07-08 14:00  E6, #1322  Ultrabroadband squeezed pulses and their relation to relativity file
374 2023-07-10 16:00  E6, #1323  Electronic structures of magnetic and non-magnetic ordering in d- and f-electrons systems
373 2024-02-16 10:00  E6, #1323  Optical conductivity of superconducting states driven by Van Hove singularities
372 2015-10-23 10:30  E6, #1501  How to write a good scientific paper[Open lecture series]
371 2022-02-28 16:00  E6, #1501  Spin-based training of optical microscopes
370 2022-03-07 16:00  E6, #1501  Climate Physics and Modelling(우리말강의)