Uniaxial magnon spin transport in electric field controlled chiral antiferromagnetic insulator

ORAL

Abstract

Magnons, elementary excitations of the magnetic order, have been manifested as ultralow energy information carriers for future technological applications such as magneto-electric spin orbit coupled logic. Bismuth ferrite (BiFeO3, BFO) is the only insulating antiferromagnet that exhibits multiple order parameters and has been demonstrated to be useful for electric field manipulation of the magnetic order [1], as well as control of magnon transport [2]. The coercive electric field in BFO, however, is large, limiting its practical usefulness. La-substitution (LBFO) has been proposed to mitigate this challenge [3], yet the effects of La-substitution on the local magnetic properties are not well understood. In this work, we experimentally demonstrate the antiferromagnetic non-local magnon spin transport in LBFO and detected via inverse spin Hall effect of Pt. While BFO exhibits well defined ferroelectric domains, LBFO has mixed ferroelectric and antiferroelectric phases and, using electrical field pulses, single ferroelectric domains can be formed. This implies the formation of single magnetic domains, which are extremely attractive for magnonic devices. We hypothesize that this is due to the 12 possible ferroelectric switching paths in LBFO, whereas only 4 possible directions exist in BFO [3]. This uniform magnetic state in a single ferroelectric domain leads to efficient spin transport, due to reduced domain wall scattering, contrary to multidomain BFO. The observed non-local magnons are highly anisotropic in-plane with respect to substrate crystallographic directions, independent of antiferromagnetic layer thickness. This observation of switchable, efficient magnon transport in LBFO is an important milestone for realizing antiferromagnetic magnons in future applications.

[1] J. T. Heron et al Nature 516, 370 (2014).

[2] Parsonnet, E. et al. Phys. Rev. Lett. 129, 087601 (2022).

[3] Yen-Lin Huang et al Nat Commun 11, 2836 (2020).

*This work was primarily supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, the Microelectronics Co-Design Research Program, under contract no. DE-AC02-05-CH11231 (Codesign of Ultra-Low-Voltage Beyond CMOS Microelectronics).

–

Presenters

  • Sajid Husain

    • Lawrence Berkeley national Laboratory

Authors

  • Sajid Husain

    • Lawrence Berkeley national Laboratory

  • Isaac A Harris

    • University of California, Berkeley

  • Peter Meisenheimer

    • University of California, Berkeley

  • Maya Ramesh

    • Cornell University

  • Hossein Taghinejad

    • University of California, Berkeley

  • Pravin Kavle

    • UC Berkeley

  • Lucas M Caretta

    • University of California, Berkeley

  • Paul Stevenson

    • Northeastern University

  • James G Analytis

    • University of California, Berkeley
    • University of California Berkeley

  • Darrell G Schlom

    • Cornell University
    • Department of Materials Science and Engineering, Cornell University

  • Sayeef Salahuddin

    • University of California, Berkeley, Lawrence Berkeley National Laboratory
    • University of California, Berkeley

  • Lane W Martin

    • University of California, Berkeley

  • Zhi (Jackie) Yao

    • Lawrence Berkeley National Laboratory

  • Ramamoorthy Ramesh

    • University of California, Berkeley