Quantum-limited charge detection with two quantum point contacts
arXiv:1101.4784 · doi:10.1103/PhysRevB.84.033404
Abstract
We present a scheme for tuning two quantum point contacts as a quantum-limited charge detector. Based on the scattering matrix approach, we analyze a general condition of quantum-limited detection with a single-channel quantum detector possessing time-reversal symmetry. From this analysis we find that quantum-limited detection can be easily realized with two quantum point contacts connected in series, which is not possible if only a single quantum point contact is used. We also discuss the sensitivity enhancement due to multiple reflections of the two point contacts.
9 pages, 2 figures
References in corpus (6)
- Quantum mechanical complementarity probed in a closed-loop Aharonov-Bohm interferometer
- Controlled Dephasing of a Quantum Dot: From Coherent to Sequential Tunneling
- Charge Detection in a Closed-Loop Aharonov-Bohm Interferometer
- Entanglement, measurement, and conditional evolution of the Kondo singlet interacting with a mesoscopic detector
- Dephasing and Measurement Efficiency via a Quantum Dot Detector
- Edge-state Fabry-Perot interferometer as a high sensitivity charge detector