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Non-Volatile Spin Wave Computing


Speaker:Prof. Jiang Xiao
Affiliation:Department of Physics, Fudan University
Date:February 1, 2018 (Thursday)
Time:4:30 p.m.
Venue:Room 522, 5/F, Chong Yuet Ming Physics Building, HKU

Abstract
 

As a collective quasiparticle excitation of the magnetic order, spin wave can propagate in both conducting and insulating materials with little dissipation. Magnetic material with non-trivia magnetic texture provides a unified information memory and processing platform [1, 2].

We demonstrate that, in the presence of Dzyaloshinskii-Moriya interaction, an antiferromagnetic domain wall acts as a spin wave polarizer or a spin wave retarder [3]. Based on the same principle, the spin wave driven domain wall motion in antiferromagnet also strongly depends on the linear polarization of the injected spin waves [4].

Furthermore, we construct functional spin wave logic devices, in which information processing is realized by manipulating spin wave polarizations. This magnonic logic gate has several advantages comparing to existing logic architectures: i) high speed, reaching the extremely high frequency of antiferromagnet (THz); ii) energy efficient, the insulator based spin wave computing can avoid electronic Joule heating completely; iii) simple design, both logic and memory parts base on a common magnetic material/system thus reducing the complexity in hardware. Following the demonstration of the functionality of individual gates, we present a function halfadder composed of two gates. [4]

The proposed theoretical scheme for a spin wave computing is intrinsically a non-von Neumann architecture with processing-in-memory.

[1]. Lan, J., Yu, W., Wu, R. & Xiao, J., Phys. Rev. X 5, 041049 (2015).
[2]. Yu, W., Lan, J., Wu, R. & Xiao, J., Phys. Rev. B 94, 140410(R) (2016).
[3]. Lan, J., Yu, W. & Xiao, J., Nature Communications 8, 178 (2017).
[4]. Yu, W., Lan, J., & Xiao, J., In preparation (2017).  
 
Coffee and tea will be served 20 minutes prior to the seminar.

Anyone interested is welcome to attend.