We investigate nonequilibrium transport in a triple-quantum-dot (TQD) system, where the central dot acts as a discrete tunnel barrier, subject to continuous monitoring by a quantum point contact (QPC) that is capacitively coupled to all three dots with independently tunable strengths. We show that this global measurement scheme affects transport in a qualitatively distinct manner from single-site measurement. By engineering structured dephasing, measurement provides a significant improvement in the barrier occupation and tunneling current. In the strong-measurement limit, the steady state becomes independent of the underlying Hamiltonian parameters, and the barrier occupation can approach 1/2 for suitable measurement configurations. We identify an optimal measurement configuration that maximizes the steady-state current and show that near-optimal performance can be achieved with a simple central-dot readout scheme.
@article{arxiv.2605.19001,
title = {Collective charge measurement in quantum dot chains: controlling barrier occupation and tunneling current},
author = {Alok Nath Singh and Rafael Sánchez and Andrew N. Jordan},
journal= {arXiv preprint arXiv:2605.19001},
year = {2026}
}