Hydrodynamic rectified drag current in a quantum wire induced by Wigner crystallization

We measure Coulomb drag between displaced parallel quantum wires fabricated on a high-mobility two-dimensional electron gas using a split-gate technique. We observe a rectified Coulomb drag, in which the sign of the drag current is the same irrespective of the current direction in the drive wire, when the Coulomb interaction becomes dominant over kinetic energy for a low electron density, a high magnetic field, and low temperature. This result strongly suggests the formation of a Wigner crystalline state in a quantum wire. We analyze the dynamical response of the Wigner crystal to an electrostatic potential created by the adjacent drive wire within a hydrodynamic framework.