The Josephson junction as a quantum engine




International Centre for Theory of Quantum Technologies (ICTQT), University of Gdańsk

November 15, 2023 12:30 PM

We treat the Cooper pairs in the superconducting electrodes of a Josephson junction (JJ) as an open system, coupled via Andreev scattering to external baths of electrons. The disequilibrium between the baths generates the direct-current bias applied to the JJ. In the weak-coupling limit we obtain a Markovian master equation that provides a simple dynamical description consistent with the main features of the JJ, including the form of the current-voltage characteristic, its hysteresis, and the appearance under periodic voltage driving of discrete Shapiro steps. For small dissipation, our model also exhibits a self-oscillation of the JJ's electrical dipole around mean voltage V. This self-oscillation, associated with "hidden attractors" of the nonlinear equations of motion, explains the observed production of monochromatic radiation.

This is a hybrid event:
Room D, the Institute of Physics PAS, Al. Lotników 32/46

Online: Zoom Link, (Passcode: 134595, Meeting ID: 823 8038 0442)