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Lee, S.*; Nakata, Koki; Tchernyshyov, O.*; Kim, S. K.*
Physical Review B, 107(18), p.184432_1 - 184432_12, 2023/05
Times Cited Count：5 Percentile：89.29(Materials Science, Multidisciplinary)We theoretically investigate the interaction between magnons and a Skyrmion-textured domain wall in a two-dimensional antiferromagnet and elucidate the resultant properties of magnon transport. Using supersymmetric quantum mechanics, we solve the scattering problem of magnons on top of the domain wall and obtain the exact solutions of propagating and bound magnon modes. Then, we find their properties of reflection and refraction in the Skyrmion-textured domain wall, where magnons experience an emergent magnetic field due to its non-trivial spin texture-induced effective gauge field. Finally, we show that the thermal transport decreases as the domain wall's chirality increases. Our results suggest that the thermal transport of an antiferromagnet is tunable by modulating the Skyrmion charge density of the domain wall.
*; Miyazaki, Tetsuro*; *; ; Aratono, Yasuyuki; Saeki, Masakatsu; Tachikawa, Enzo
Journal of Physical Chemistry, 95(4), p.1651 - 1654, 1991/00
Times Cited Count：5 Percentile：25.38(Chemistry, Physical)no abstracts in English
; *; *;
J.Phys.,B, 11(6), p.1039 - 1048, 1978/06
no abstracts in English
Nakata, Koki
no journal, ,
Recently, non-Hermitian quantum mechanics has been attracting considerable attention. The key concepts of quantum mechanics are quantum fluctuations. Quantum fluctuations of quantum fields confined in a finite-size system induce the zero-point energy shift. This quantum phenomenon, the Casimir effect, is one of the most striking phenomena of quantum mechanics in the sense that there are no classical analogs and has been drawing much attention from various research areas, including high energy physics, beyond the hierarchy of energy scales. However, the non-Hermitian extension of the Casimir effect and the application to spintronics remain missing ingredients. Here we fill this gap. By developing a magnonic analog of the Casimir effect into non-Hermitian systems, we show that energy dissipation serves as a key ingredient of Casimir engineering to control and manipulate the Casimir effect of magnons.
Nakata, Koki
no journal, ,
Recently, there has been a growing interest in non-Hermitian quantum mechanics. However, the non-Hermitian extension of the Casimir effect and the application to spintronics remain missing ingredients. Here we fill this gap. By developing a magnonic analog of the Casimir effect into non-Hermitian systems, we show that this non-Hermitian Casimir effect of magnons is enhanced as the Gilbert damping constant (i.e., the energy dissipation rate) increases. When the damping constant exceeds a critical value, the non-Hermitian Casimir effect of magnons exhibits an oscillating behavior, including a beating one, as a function of the film thickness and is characterized by the exceptional point. Our result suggests that energy dissipation serves as a key ingredient of Casimir engineering.
Nakata, Koki
no journal, ,
Recently, there has been a growing interest in non-Hermitian quantum mechanics. However, the non-Hermitian extension of the Casimir effect and the application to spintronics remain missing ingredients. Here we fill this gap. By developing a magnonic analog of the Casimir effect into non-Hermitian systems, we show that this non-Hermitian Casimir effect of magnons is enhanced as the Gilbert damping constant (i.e., the energy dissipation rate) increases. When the damping constant exceeds a critical value, the non-Hermitian Casimir effect of magnons exhibits an oscillating behavior, including a beating one, as a function of the film thickness and is characterized by the exceptional point. Our result suggests that energy dissipation serves as a key ingredient of Casimir engineering.
Josephson junctions and its non-Hermitian Josephson diode effectNakata, Koki
no journal, ,
