Giant gate response of the charge in an electron–lattice condensate

Abstract

Charge-density-wave condensates are correlated electronic phases in which strong electron–lattice interactions lead to collective charge behaviour. Efficient electrical control of these condensates could enable gating beyond conventional capacitive limits. Here we report a giant gate response of the condensate density in the quasi-one-dimensional material orthorhombic tantalum trisulfide (o-TaS3). The gate-induced change in the condensate charge density exceeds predictions based on geometrical gate capacitance by one to two orders of magnitude. The enhanced gating effect arises from the coupling of the electric field to the electron–lattice condensate, which amplifies the gate response by means of collective electronic behaviour. We quantify the effect by determining the quantum capacitance of the charge-density-wave and by constructing a band diagram for the gated charge-density-wave device. The carrier density of a charge-density-wave condensate can be directly and strongly modulated by electrical gating in orthorhombic tantalum trisulfide nanowires.