Search for: All records

Self-regulation of free charge carriers in perovskitesviaSchottky defect formation has been posited as the origin of the well-known defect-tolerance of metal halide perovskite materials. 

The Unruh-DeWitt particle detector model has found success in demonstrating quantum information channels with non-zero channel capacity between qubits and quantum fields. These detector models provide the necessary framework for experimentally realizable Unruh-DeWitt quantum computers with near-perfect channel capacity. We propose spin-qubits with gate-controlled coupling to Luttinger liquids as a laboratory setting for Unruh-DeWitt detectors and explore general design constraints that underpin their feasibility in this and other settings. We present several experimental scenarios including graphene ribbons, edges states in the quantum spin Hall phase of HgTe quantum wells, and the recently discovered quantum anomalous Hall phase in transition metal dichalcogenides. Theoretically, through bosonization, we show that Unruh-DeWitt detectors can carry out quantum computations and identify when they can make perfect quantum communication channels between qubits via the Luttinger liquid. Our results point the way toward an all-to-all connected solid state quantum computer and the experimental study of quantum information in quantum fields via condensed matter physics. 

Kelvin probe force microscopy (KPFM) experiments are used to image capacitance and surface potential in a wide variety of samples. The widely used KPFM frequency-shift equation rests on assumptions that are questionable in samples having an appreciable impedance or whose properties evolve on a fast timescale. We present new equations describing the cantilever frequency and dissipation in a KPFM experiment carried out on a sample with an appreciable stationary or time-dependent impedance, such as a photovoltaic film, a battery material, or a mixed electronic-ionic conductors.