Cavity Spintronics: Bringing Together Magnetism with Quantum Technologies

Can-Ming Hu, University of Manitoba

February 26, 2021

Cavity Spintronics [1] (also known as Cavity Magnonics and Spin Cavitronics) is an emerging field that studies the strong coupling between cavity photons and collective spin excitations such as magnons. Via the quantum physics of spin-photon entanglement on the one hand, and classical electrodynamic coupling on the other, magnon-photon coupling connects some of the most exciting modern physics, such as quantum information and quantum optics, with one of the oldest science on the earth, the magnetism.

 This talk aims to introduce this frontier at the level of undergraduate physics. Starting with the intuitive example of coupled harmonic oscillators, I will explain the concepts of coherent and dissipative couplings, based on which two streams of current research will be presented: (i) The development of diverse quantum transducers utilizing coherent coupling [2]. (ii) The study of dissipative coupling [3] governed by a non-Hermitian Hamiltonian, which leads to intriguing effects such as exceptional points [4], bound states in continuum [4], nonreciprocal microwave transmission [5], and level attraction [6]. Physics or engineering students who are looking for frontier research opportunities are encouraged to attend.

[1] C.-M. Hu, Phys. in Canada, 72, No. 2, 76 (2016); arXiv: 1508.01966 (2015).
[2] D. Lachance-Quirion et al., Appl. Phys. Express 12, 070101 (2019).
[3] Yi-Pu Wang and Can-Ming Hu, J. Appl. Phys. 127, 130901 (2020).
[4] Y. Yang et al., Phys. Rev. Lett., 125, 147202 (2020).
[5] Y.-P. Wang et al., Phys. Rev. Lett., 123, 127202 (2019).
[6] M. Harder et al., Phys. Rev. Lett., 121, 137203 (2018).