title: Evidence for interacting two-level systems from the 1/f noise of a superconducting resonator.
abstract: The performance of a great variety of electronic devices--ranging from semiconductor transistors to superconducting qubits--is hampered by low-frequency noise with spectra proportional to 1/f. The ubiquity and negative impact of 1/f noise has motivated intensive research into its cause, and it is now believed to originate from a bath of fluctuating two-level defect states (TLSs) embedded in the material. This phenomenon is commonly described by the long-established standard tunnelling model (STM) of independent TLS. A key prediction of STM is that the noise should vanish at low temperatures. Here we report measurements on superconducting microresonators over previously unattainable, very long time scales that show an increase in 1/f noise at low temperatures and low microwave power, contrary to the STM. We propose a new generalised tunnelling model that includes significant interaction between multiple TLSs, which fully describes these observations, as well as recent studies of individual TLS lifetimes in superconducting qubits.
authors.affiliation: 1] National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK [2] Royal Holloway, University of London, Egham TW20 0EX, UK.
authors.forename: J
authors.initials: J
authors.lastname: Burnett
authors.affiliation: 1] Laboratoire de Physique Theorique et Hautes Energies, CNRS UMR 7589, Universites Paris 6 et 7, 4 place Jussieu, Paris 75252, Cedex 05, France [2] Department of Physics and Astronomy, Rutgers The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, USA.
authors.forename: L
authors.initials: L
authors.lastname: Faoro
authors.affiliation: 1] National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK [2] Royal Holloway, University of London, Egham TW20 0EX, UK.
authors.forename: I
authors.initials: I
authors.lastname: Wisby
authors.affiliation: Institute of Microelectronics Technology and High Purity Materials, Academician Ossipyan strasse, 6, Chernogolovka, Moscow 142432, Russia.
authors.forename: V L
authors.initials: VL
authors.lastname: Gurtovoi
authors.affiliation: Institute of Microelectronics Technology and High Purity Materials, Academician Ossipyan strasse, 6, Chernogolovka, Moscow 142432, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Chernykh
authors.affiliation: Institute of Microelectronics Technology and High Purity Materials, Academician Ossipyan strasse, 6, Chernogolovka, Moscow 142432, Russia.
authors.forename: G M
authors.initials: GM
authors.lastname: Mikhailov
authors.affiliation: Institute of Microelectronics Technology and High Purity Materials, Academician Ossipyan strasse, 6, Chernogolovka, Moscow 142432, Russia.
authors.forename: V A
authors.initials: VA
authors.lastname: Tulin
authors.affiliation: Royal Holloway, University of London, Egham TW20 0EX, UK.
authors.forename: R
authors.initials: R
authors.lastname: Shaikhaidarov
authors.affiliation: Royal Holloway, University of London, Egham TW20 0EX, UK.
authors.forename: V
authors.initials: V
authors.lastname: Antonov
authors.affiliation: Royal Holloway, University of London, Egham TW20 0EX, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Meeson
authors.affiliation: 1] National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK [2] Royal Holloway, University of London, Egham TW20 0EX, UK.
authors.forename: A Ya
authors.initials: AY
authors.lastname: Tzalenchuk
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK.
authors.forename: T
authors.initials: T
authors.lastname: Lindström