Decoherence of the Kondo Singlet via a Quantum Point Contact Detector
arXiv:cond-mat/0501725 · doi:10.1103/PhysRevLett.95.206808
Abstract
We investigate the effect of the charge state measurement of the Kondo singlet for a quantum dot transistor via a capacitively coupled quantum point contact detector. By employing the variational ansatz for the singlet ground state of the quantum dot combined with the density matrix formulation for the coupled system, we show that the coherent Kondo singlet is destroyed by the phase-sensitive as well as the magnitude-sensitive detection in the transmission/reflection coefficients at the quantum point contact. We argue that the phase-sensitive component of the decoherence rate may explain the anomalous features observed in a recent experiment by Avinun-Kalish {\em et al.} (Phys. Rev. Lett. {\bf 92}, 156801 (2004)). We also discuss the correlations of the shot noise at the quantum point contact detector and the decoherence in the quantum dot.
References in corpus (1)
Cited by in corpus (13)
- Quantum mechanical complementarity probed in a closed-loop Aharonov-Bohm interferometer
- On the validity and breakdown of the Onsager symmetry in mesoscopic conductors interacting with environments
- Controlled dephasing in single-dot Aharonov-Bohm interferometers
- An Electronic Mach-Zehnder Quantum Eraser
- 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
- Dephasing in a quantum dot coupled to a quantum point contact
- Backaction Dephasing by a Quantum Dot Detector
- Quantum-limited charge detection with two quantum point contacts
- Edge-state Fabry-Perot interferometer as a high sensitivity charge detector
- Nonequilibrium transport through an interacting monitored quantum dot
- Ultimate charge sensitivity and efficiency of a quantum point contact with a superposed input state