Sequential measurement of displacement and conduction currents in electronic devices

TL;DR

This paper extends the Ramo-Schockley-Pellegrini theorem to quantum systems, defining a POVM for total current measurement, and demonstrates its implementation and sensitivity analysis in a quantum electron transport simulator.

Contribution

It introduces a quantum measurement framework for displacement and conduction currents, bridging weak and strong measurement regimes, and applies it to simulate quantum electron transport.

Findings

Measurement sensitivity depends on Gaussian width and measurement interval.

The framework unifies weak and projective measurement schemes.

Numerical simulations show parameter influence on current-voltage characteristics.

Abstract

The extension of the Ramo-Schockley-Pellegrini theorem for quantum systems allows to define a positive-operator valued measure (POVM) for the total conduction plus displacement electrical current. The resulting current operator is characterized by two parameters, viz. the width of the associated Gaussian functions and the lapse of time between consecutive measurements. For large Gaussian dispersions and small time intervals, the operator obeys to a continuous weak-measurement scheme. Contrarily, in the limit of very narrow Gaussian widths and a single-shot measurement, the operator corresponds to a standard von Neumann (projective) measurement. We have implemented the resulting measurement protocol into a quantum electron transport simulator. Numerical results for a resonant tunneling diode show the great sensibility of current-voltage characteristics to different parameter configurations of the total current operator.