Abstract
The paper reassesses the old dilemma “compact vs. extended phase” in the quantum theory of the rotator and the Josephson junction and the analogy of these two systems with a particle moving in a periodic potential. This dilemma is in fact the dilemma whether the states with the phases φ and φ + 2π are distinguishable, or not. In the past it was widely accepted that in the Josephson junction these states are distinguishable like for a particle moving in a periodic potential. This paper argues that the states with the phases φ and φ + 2π are indistinguishable as in a pendulum (a particular example of the quantum rotator). However, this does not lead to revision of the conclusions of the conventional theory predicting the transition from the superconducting to the insulating state in the small Josephson junction.
Original language | English |
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Pages (from-to) | 450-463 |
Number of pages | 14 |
Journal | Fizika Nizkikh Temperatur |
Volume | 48 |
Issue number | 5 |
DOIs | |
State | Published - May 2022 |
Bibliographical note
Publisher Copyright:© Edouard B. Sonin, 2022
Keywords
- dissipative quantum phase transition
- Josephson junction
- quantum rotator