Decoherence in Nearly-Isolated Quantum Dots
When a quantum dot is isolated from the environment by closing off its leads, the rate at which the electrons in the dot lose phase coherence is expected to drop essentially to zero for sufficiently low temperatures. While it is widely accepted that that the coherence time will diverge for temperatures below the mean level spacing D in a device, Altshuler et al [Phys. Rev. Lett. 78, 2803 (1997)] have predicted no dephasing even at temperatures as large as D. N1/4.
Research is continuing in both smaller and larger devices. Among other things, we will measure whether decoherence remains vanishingly small at temperatures less thanD.
For more information contact Joshua Folk (jfolk@stanford.edu)