Theory of double Cooper-pair tunneling and light emission mediated by a resonator

Anno: 2019

Autori: Morley W.T., Di Marco A., Mantovani M., Stadler P., Belzig W., Rastelli G., Armour A.D.

Affiliazione autori: Univ Nottingham, Ctr Math & Theoret Phys Quantum Nonequilibrium Sy, Nottingham NG7 2RD, England. Univ Nottingham, Sch Phys & Astron, Nottingham NG7 2RD, England. Univ Konstanz, Fachbereich Phys, D-78457 Constance, Germany. Chalmers Univ Technol, Dept Microtechnol & Nanosci MC2, SE-41298 Gothenburg, Sweden. Univ Konstanz, Zukunftskolleg, D-78457 Constance, Germany.

Abstract: Photon emission by tunneling electrons can be encouraged by locating a resonator close to the tunnel junction and applying an appropriate voltage bias. However, studies of normal metals show that the resonator also affects how the charges flow, facilitating processes in which correlated tunneling of two charges produces one photon. We develop a theory to analyze this kind of behavior in Josephson junctions by deriving an effective Hamiltonian describing processes where two Cooper pairs generate a single photon. We determine the conditions under which the transport is dominated by incoherent tunneling of two Cooper pairs, while also uncovering a regime of coherent double Cooper-pair tunneling. We show that the system can also display an unusual form of photon blockade and hence could serve as a single-photon source.

Giornale/Rivista: PHYSICAL REVIEW B

Volume: 100 (5)      Da Pagina: 054515  A: 054515

Maggiori informazioni: We thank J. Ankerhold, B. Kubala, B. Lang, and F. Portier for useful discussions. This work was supported by the Engineering and Physical Sciences Research Council (Grant No. EP/P510592/1) through a studentship held by W.T.M., by the Leverhulme Trust through a research project grant (Grant No. RPG-2018-213), by the German Excellence Initiative through the Zukunftskolleg and the Deutsche Forschungsgemeinschaft (DFG) through the SFB 767.
Parole chiavi: Josephson junctions, quantum microwave circuits, quantum radiation
DOI: 10.1103/PhysRevB.100.054515