Engineering the speedup of quantum tunneling in Josephson systems via dissipation

4 Oct 2022, 18:00
30m
Sala Stringa (FBK (Trento, Italy))

Sala Stringa

FBK (Trento, Italy)

Via Sommarive, 18, 38123 Povo TN
ORAL Talks

Speaker

Gianluca Rastelli (CNR-INO & Univerity of Trento)

Description

It is common sense that when a quantum coherent system is not perfectly isolated from the environment, quantum effects are destroyed and the system fundamentally follows the classical mechanics’ rules. This is not always the case. Indeed, the dissipative interaction, namely the interaction between a quantum system and its external bath, can lead to an enhancement of quantum effects.

In this work [1] we show that a such situation can occur in a superconducting Josephson circuit with an extremely simple scheme to achieve the opportune dissipation that plays the desired game. In our proposal, we show that the engineered electromagnetic environment formed by the external impedances and coupled to a current bias Josephson current can enhance the quantum tunneling of the superconducting phase from a metastable state. This environmental assisted quantum tunneling can therefore speed up the relaxation dynamics of the phase towards the absolute energy minimum. This provides a proof of concept opening the route for the promising perspective of using quantum dissipative Josephson circuits as quantum simulators for optimization problems.

[1] https://arxiv.org/abs/2203.08705,
accepted in Phys. Rev. B
https://journals.aps.org/prb/accepted/5a07cO56D8d1cb4794a426b6bf98688ac3c032d68

Primary authors

Gianluca Rastelli (CNR-INO & Univerity of Trento) Dr Dominik Maile (Institut für komplexe Quantensysteme, Universität Ulm, D-89069 Ulm, Germany) Prof. Joachim Ankerhold (Institut für komplexe Quantensysteme, Universität Ulm, D-89069 Ulm, Germany) Prof. Sabine Andergassen (Institut für Theoretische Physik and Center for Quantum Science, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany) Prof. Wolfgang Belzig (Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany)

Presentation materials