Large-Voltage Tuning of Dzyaloshinskii-Moriya Interactions: A Route toward Dynamic Control of Skyrmion Chirality

Nano Lett. 2018 Aug 8;18(8):4871-4877. doi: 10.1021/acs.nanolett.8b01502. Epub 2018 Jul 3.

Abstract

Electric control of magnetism is a prerequisite for efficient and low-power spintronic devices. More specifically, in heavy metal-ferromagnet-insulator heterostructures, voltage gating has been shown to locally and dynamically tune magnetic properties such as interface anisotropy and saturation magnetization. However, its effect on interfacial Dzyaloshinskii-Moriya Interaction (DMI), which is crucial for the stability of magnetic skyrmions, has been challenging to achieve and has not been reported yet for ultrathin films. Here, we demonstrate a 130% variation of DMI with electric field in Ta/FeCoB/TaO x trilayer through Brillouin Light Spectroscopy (BLS). Using polar magneto-optical Kerr-effect microscopy, we further show a monotonic variation of DMI and skyrmionic bubble size with electric field with an unprecedented efficiency. We anticipate through our observations that a sign reversal of DMI with an electric field is possible, leading to a chirality switch. This dynamic manipulation of DMI establishes an additional degree of control to engineer programmable skyrmion-based memory or logic devices.

Keywords: Dzyaloshinskii−Moriya interaction; chirality; electric field effects; perpendicular magnetic anisotropy; skyrmions.

Publication types

  • Research Support, Non-U.S. Gov't