High-Frequency Dynamics in Antiferromagnetic Sr₃Ir₂O₇

PAPER: Heidi Seinige, Morgan Williamson, Shida Shen, Cheng Wang, Gang Cao, Jianshi Zhou, John B. Goodenough, Maxim Tsoi,

“Electrically tunable transport and high-frequency dynamics in antiferromagnetic Sr₃Ir₂O₇”.

ABSTRACT:

We report dc and high-frequency transport properties of antiferromagnetic Sr₃Ir₂O₇. Temperature-dependent resistivity measurements show that the activation energy of this material can be tuned by an applied dc electrical bias. The latter allows for continuous variations in the sample resistivity of as much as 50% followed by a reversible resistive switching at higher biases. Such a switching is of high interest for antiferromagnetic applications in high-speed memory devices. Interestingly, we found the switching behavior to be strongly affected by a high-frequency (microwave) current applied to the sample. The microwaves at 3-7 GHz suppress the dc switching and produce resonance-like features that we tentatively associated with the dissipationless magnonics recently predicted to occur in antiferromagnetic insulators subject to ac electric fields. We have characterized the effects of microwave irradiation on electronic transport in Sr₃Ir₂O₇ as a function of microwave’s frequency and power, strength and direction of external magnetic field, strength and polarity of applied dc bias, and temperature. Our observations support the potential of antiferromagnetic materials for high-speed/high-frequency spintronic applications.

This work was supported in part by C-SPIN, one of six centers of STARnet, a Semiconductor Research Corporation program, sponsored by MARCO and DARPA, by NSF grants DMR-1207577, DMR-1265162, DMR-1600057, and DMR-1122603, and by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No. OSR-2015-CRG4-2626