Dresden 2017 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 19: Poster Session: Correlated Electrons 1
TT 19.18: Poster
Monday, March 20, 2017, 15:00–19:00, P2-EG
Phase diagram of the quantum dissipative rotor model with two competing baths — •Dominik Maile1, Sabine Andergassen1, Wolfgang Belzig2, and Gianluca Rastelli2 — 1Eberhard Karls Universität Tübingen, D-72074 Tübingen, Germany — 2Universität Konstanz, D-78457 Konstanz, Germany
We study a quantum dissipative rotor model in which each local phase-difference and each local momentum are uniformly coupled to two different baths. Such systems can represent e.g. a chain of resistively shunted Josephson junctions [1], capacitively coupled to a diffusive metal [2]. The first dissipative coupling quenches the quantum phase fluctuations favoring the long-range phase order (i.e. superconducting ground state) whereas the second one quenches momentum fluctuations destroying phase coherence (insulating ground state).
Using the Self-Consistent Harmonic Approximation [1], we calculate the zero-temperature phase diagram as determined by the two dissipative coupling constants and the bare zero point fluctuations. As an effect of the quantum frustration for the two canonical conjugate observables [3], we obtain an interesting phase diagram with a non-monotonic behavior: for instance, the ground state can pass from superconducting to insulating phase and back to superconducting phase by increasing the dissipation.
[1] S. Chakravarty et al., Phys. Rev. Lett. 56, 2303 (1986).
[2] A.M.Lobos, T. Giamarchi, Phys. Rev. B 84, 024523 (2011).
[3] G. Rastelli, New J. Phys. 18, 053033 (2016).