Unconventional hysteresis from electron correlation and lattice incommensurability in Nb₃Cl₈/graphene heterostructure

As a key phenomenon in condensed matter physics, resistance hysteresis signifies various unconventional phases, and underpins modern memory devices. The discovery and understanding of new hysteresis behavior advances both fundamental physics and the development of the next-generation non-volatile memory devices. Here we report an unexpected resistance hysteresis triggered by the back gate in Nb₃Cl₈/monolayer graphene (MLG) heterostructure, a prototype of artificial heavy fermion system. The hysteresis exhibits an asymmetric L-shape, which can be modulated by the back-gate sweep range. Through a control experiment that suppresses the Nb₃Cl₈/MLG coupling by inserting a thin h-BN between Nb₃Cl₈ and MLG, the critical role of the interface is established. Dual-gate mapping and back gate-temperature mapping of resistance further reveal the profound relation between the hysteresis and charge transfer behaviors induced by heavy fermion physics. To explain all these experimental observations, we propose a "virtual floating-gate model", where the heavy fermion physics prolongs the relaxation time of charge on Nb₃Cl₈ states, and the incommensurate lattices of the heterostructure lead to charge transfer domain formation. Our work unveils novel hysteresis mechanism arising from the interplay between strong electron interactions and incommensurate lattices, paving the way for the next-generation electronic devices.