QUANTUM ADIABATIC TRANSPORT IN THE PRESENCE OF A FINITE-TEMPERATURE ELECTRODYNAMIC ENVIRONMENT

We investigate the influence of electromagnetic fluctuations on quantu m transport in a two-dimensional electron gas. We calculate the conduc tance of a quantum point contact under the influence of transport and gate-voltage fluctuations at finite temperature, using a generalized L andauer-Buttiker approach. The fluctuations are described by a suitabl e bath of bosons. In contrast to fluctuations of the gate-voltage, tra nsport voltage fluctuations can completely block the electron transpor t at T = 0. This blockade is lifted as a result of finite temperature of the electrons in the Fermi reservoirs and also of the coupled boson s. In a typical experiment, these two temperatures need not to be the same. We show that the temperature of the coupled bosons limits the ac curacy of the conductance quantization of a quantum point contact to a few percent.