Magnetic insulators, which have long-range magnetic order and are electrically insulating, allow spin propagation without electron motion and could be used to create dissipationless magnetoelectric and magneto-optical devices. Atomically thin two-dimensional (2D) magnetic insulators could, in particular, be used to fabricate compact devices. However, the efficient electrical control of 2D magnetic insulators remains a challenge due to difficulties in electrostatically doping such insulators and the inability of external electric fields to modify their crystal fields. Here we report the electrical control of the 2D magnetic insulator chromium germanium telluride (Cr2Ge2Te6) using a thin ferroelectric polymer. We show that ±5 V across the Cr2Ge2Te6/polymer heterostructures can open and close the magnetic hysteresis loop. The magnetic modulation is non-volatile, and is observed in bilayer, trilayer and four-layer Cr2Ge2Te6, but not in thicker eight-layer Cr2Ge2Te6, which indicates the importance of the interfacial multiferroic effect. The heterostructure multiferroics also enable direct electrical toggling between two magnetization states.
Bibliographical noteFunding Information:
C.G. acknowledges support from the Air Force Office of Scientific Research under award no. FA9550-22-1-0349, Naval Air Warfare Center Aircraft Division under award no. N00421-22-1-0001, Army Research Laboratory under cooperative agreement no. W911NF-19-2-0181, National Science Foundation under award nos. CMMI-2233592 and 49100423C0011, and Northrop Grumman Mission Systems’ University Research Program. I.Ž. acknowledges support from the Air Force Office of Scientific Research under award no. FA9550-22-1-0349 and National Science Foundation under award nos. CMMI-2233375 and ECCS-2130845. S.-J.G. acknowledges support from the National Natural Science Foundation of China under award no. 62274066. J.-P.W. acknowledges support from the Robert F. Hartmann Endowed Chair Professorship. M.A.S. and B.S.C. acknowledge support from the United States Air Force Office of Scientific Research LRIR 18RQCOR100 and AOARD-MOST grant no. F4GGA21207H002. B.S.C. further acknowledges the National Research Council Senior Fellowship award. C.G. is grateful for the fruitful discussions with J. Chang, R. Howell and Q. Zhang.
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