Study of operation of the coherent superconducting phase slip centres

Speaker: Prof. Vladimir Anotonov (Royal Holloway University of London)

Abstract: We study superconducting coherent quantum phase slip (CQPS) centres which enable us to explore the fundamental charge-phase duality in superconductors. It also promises devices with new functionalities, like robust quantum current standard and the Charge Quantum Interference Device (CQUID). The operation of superconducting wires in a regime of the coherent phase slip centre was enlighten by Mooj and Nazarov back in 2006 followed by the experimental demonstration by Astafiev et al in 2012. In the experiment the wire with CQPS replaced Josephson Junction as the non-linear element in the flux qubit: the phase slip energy E_Sentered the Hamiltonian instead of E_J. Further development of the phenomenon was modulation of E_S with the induced charge, dual to modulation of E_J with the flux by S. E. de Graaf et all in 2018. Recently efforts were invested to utilize CQPS for the current standard. The road to success lies in arranging a specific electromagnetic environment enabling an effective coupling for the CQPS to the drive frequency and isolating from the external noise at the same time.