Quantum measurement of coherent tunneling between quantum dots
Abstract
We describe the conditional and unconditional dynamics of two coupled quantum dots when one dot is subjected to a measurement of its occupation number by coupling it to a third readout dot via the Coulomb interaction. The readout dot is coupled to source and drain leads under weak bias, and a tunnel current flows through a single bound state when energetically allowed. The occupation of the quantum dot near the readout dot shifts the bound state of the readout dot from a low conducting state to a high conducting state. The measurement is made by continuously monitoring the tunnel current through the readout dot. We show that there is a difference between the time scale for the measurement-induced decoherence between the localized states of the dots, and the time scale on which the system becomes localized due to the measurement.
- Publication:
-
Physical Review B
- Pub Date:
- June 2001
- DOI:
- 10.1103/PhysRevB.63.235308
- arXiv:
- arXiv:cond-mat/0002279
- Bibcode:
- 2001PhRvB..63w5308W
- Keywords:
-
- 85.35.Gv;
- 03.67.Lx;
- Single electron devices;
- Quantum computation;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Quantum Physics
- E-Print:
- 12 pages, 7 figures