Publications (36)
Theory of microwave spectroscopy of Andreev bound states with a Josephson junction
L. Bretheau, Ã. Girit, M. Houzet +3
We present a microscopic theory for the current through a tunnel Josephson junction coupled to a non-linear environment, which consists of an Andreev two-level system coupled to a…
Effects of the measurement power on states discrimination and dynamics in a circuit-QED experiment
L. Tosi, I. Lobato, M. F. Goffman +3
We explore the effects of driving a cavity at a large photon number in a circuit-QED experiment where the ``matter-like'' part corresponds to an unique Andreev level in a supercond…
Signatures of interactions in the Andreev spectrum of nanowire Josephson junctions
F. J. Matute-Cañadas, C. Metzger, Sunghun Park +7
We performed microwave spectroscopy of an InAs nanowire between superconducting contacts implementing a finite-length, multi-channel Josephson weak link. Certain features in the sp…
Phase controlled superconducting proximity effect probed by tunneling spectroscopy
H. Le Sueur, P. Joyez, H. Pothier +2
Using a dual-mode STM-AFM microscope operating below 50mK we measured the Local Density of States (LDoS) along small normal wires connected at both ends to superconductors with dif…
Probing interactions in mesoscopic gold wires
F. Pierre, H. Pothier, D. Esteve +3
We have measured in gold wires the energy exchange rate between quasiparticles, the phase coherence time of quasiparticles and the resistance vs. temperature, in order to probe the…
Supercurrent Spectroscopy of Andreev States
L. Bretheau, C. O. Girit, C. Urbina +2
We measure the excitation spectrum of a superconducting atomic contact. In addition to the usual continuum above the superconducting gap, the single particle excitation spectrum co…
Superconducting atomic contacts inductively coupled to a microwave resonator
C. Janvier, L. Tosi, Ã. Ã. Girit +3
We describe and characterize a microwave setup to probe the Andreev levels of a superconducting atomic contact. The contact is part of a superconducting loop inductively coupled to…
Circuit-QED with phase-biased Josephson weak links
C. Metzger, Sunghun Park, L. Tosi +6
By coupling a superconducting weak link to a microwave resonator, recent experiments probed the spectrum and achieved the quantum manipulation of Andreev states in various systems.…
Energy redistribution between quasiparticles in mesoscopic silver wires
F. Pierre, H. Pothier, D. Esteve +1
We have measured with a tunnel probe the energy distribution function of quasiparticles in silver diffusive wires connected to two large pads (``reservoirs''), between which a bias…
Spin-orbit splitting of Andreev states revealed by microwave spectroscopy
L. Tosi, C. Metzger, M. F. Goffman +6
We have performed microwave spectroscopy of Andreev states in superconducting weak links tailored in an InAs-Al (core-full shell) epitaxially-grown nanowire. The spectra present di…
Coherent manipulation of Andreev states in superconducting atomic contacts
C. Janvier, L. Tosi, L. Bretheau +9
Coherent control of quantum states has been demonstrated in a variety of superconducting devices. In all these devices, the variables that are manipulated are collective electromag…
Superconducting Quantum Point Contacts
L. Bretheau, Ã. Girit, L. Tosi +5
We review our experiments on the electronic transport properties of atomic contacts between metallic electrodes, in particular superconducting ones. Despite ignorance of the exact…
Voltage-induced Shapiro steps in a superconducting multi-terminal structure
J. C. Cuevas, H. Pothier
When a superconducting tunnel junction at a finite voltage is irradiated with microwaves, the interplay between the alternating Josephson current and the ac field gives rise to ste…
Dynamics of quasiparticle trapping in Andreev levels
D. G. Olivares, L. Bretheau, Ã. Ã. Girit +3
We present a theory describing the trapping and untrapping of quasiparticles in the Andreev bound level of a single-channel weak link between two superconductors. We calculate the…
Measurement of the current-phase relation of superconducting atomic contacts
M. L. Della Rocca, M. Chauvin, B. Huard +3
We have probed the current-phase relation of an atomic contact placed with a tunnel junction in a small superconducting loop. The measurements are in quantitative agreement with th…
Conduction Channels of an InAs-Al nanowire Josephson weak link
M. F. Goffman, C. Urbina, H. Pothier +3
We present a quantitative characterization of an electrically tunable Josephson junction defined in an InAs nanowire proximitized by an epitax-ially-grown superconducting Al shell.…
Electron heating in metallic resistors at sub-Kelvin temperature
B. Huard, H. Pothier, D. Esteve +1
In the presence of Joule heating, the electronic temperature in a metallic resistor placed at sub-Kelvin temperatures can significantly exceed the phonon temperature. Electron cool…
Effect of Magnetic Impurities on Energy Exchange between Electrons
B. Huard, A. Anthore, Norman O. Birge +2
In order to probe quantitatively the effect of Kondo impurities on energy exchange between electrons in metals, we have compared measurements on two silver wires with dilute magnet…
Influence of Magnetic Field on Effective Electron-Electron Interactions in a Copper Wire
A. Anthore, F. Pierre, H. Pothier +2
We have measured in a copper wire the energy exchange rate between quasiparticles as a function of the applied magnetic field. We find that the effective electron-electron interact…
Josephson junctions as detectors for non-Gaussian noise
B. Huard, H. Pothier, Norman O. Birge +3
Non-Gaussian fluctuations of the electrical current can be detected with a Josephson junction placed on-chip with the noise source. We present preliminary measurements with an NIS…
Comparison of energy and phase relaxation in metallic wires
A. B. Gougam, F. Pierre, H. Pothier +2
We have measured the phase coherence time, in long, narrow wires of Au, Ag, and Cu, over the temperature range 40 mK-6 K. In the Cu and Au wires, saturates at low…
Asymmetric noise probed with a Josephson junction
Q. Le Masne, H. Pothier, Norman O. Birge +2
Fluctuations of the current through a tunnel junction are measured using a Josephson junction. The current noise adds to the bias current of the Josephson junction and affects its…
FerBo: a noise resilient qubit hybridizing Andreev and fluxonium states
J. J. Caceres, D. Sanz Marco, J. Ortuzar +6
We propose a novel superconducting quantum circuit that should be robust against both relaxation and dephasing over a wide and experimentally accessible parameter range. The circui…
Searching for thermal signatures of persistent currents in normal metal rings
Germain Souche, Julien Huillery, H. Pothier +4
We introduce a calorimetric approach to probe persistent currents in normal metal rings. The heat capacity of a large ensemble of silver rings is measured by nanocalorimetry under…
Bloch Oscillations in a Josephson Circuit
N. Boulant, G. Ithier, F. Nguyen +5
Bloch oscillations predicted to occur in current-biased single Josephson junctions have eluded direct observation up to now. Here, we demonstrate similar Bloch oscillations in a sl…
Rabi oscillations, Ramsey fringes and spin echoes in an electrical circuit
D. Vion, A. Aassime, A. Cottet +5
We present a superconducting tunnel junction circuit which behaves as a controllable atom, and whose ground and first excited state form an effective spin 1/2. By applying microwav…
Manipulating the Quantum State of an Electrical Circuit
D. Vion, A. Aassime, A. Cottet +5
We have designed and operated a superconducting tunnel junction circuit that behaves as a two-level atom: the ``quantronium''. An arbitrary evolution of its quantum state can be pr…
Evidence for long-lived quasiparticles trapped in superconducting point contacts
M. Zgirski, L. Bretheau, Q. Le Masne +3
We have observed that the supercurrent across phase-biased, highly transmitting atomic size contacts is strongly reduced within a broad phase interval around Ï. We attribute this…
Current to frequency conversion in a Josephson circuit
F. Nguyen, N. Boulant, G. Ithier +4
The voltage oscillations which occur in an ideally current-biased Josephson junction, were proposed to make a current standard for metrology. We demonstrate similar oscillations in…
Ground state phase diagram and "parity flipping'' microwave transitions in a gate-tunable Josephson Junction
M. R. Sahu, F. J. Matute-Cañadas, M. Benito +6
We probed a gate-tunable InAs nanowire Josephson weak link by coupling it to a microwave resonator. Tracking the resonator frequency shift when the weak link is close to pinch-off,…
From adiabatic to dispersive readout of quantum circuits
Sunghun Park, C. Metzger, L. Tosi +4
Spectral properties of a quantum circuit are efficiently read out by monitoring the resonance frequency shift it induces in a microwave resonator coupled to it. When the two system…
Superconducting atomic contacts under microwave irradiation
M. Chauvin, P. Vom Stein, H. Pothier +4
We have measured the effect of microwave irradiation on the dc current-voltage characteristics of superconducting atomic contacts. The interaction of the external field with the ac…
Dephasing of Electrons in Mesoscopic Metal Wires
F. Pierre, A. B. Gougam, A. Anthore +3
We have extracted the phase coherence time of electronic quasiparticles from the low field magnetoresistance of weakly disordered wires made of silver, copper and gold. In…
Intensity of Coulomb Interaction between quasiparticles in diffusive metallic wires
B. Huard, A. Anthore, F. Pierre +3
The energy dependence and intensity of Coulomb interaction between quasiparticles in metallic wires is obtained from two different methods: determination of the temperature depende…
Density of states in a superconductor carrying a supercurrent
A. Anthore, H. Pothier, D. Esteve
We have measured the tunneling density of states (DOS) in a superconductor carrying a supercurrent or exposed to an external magnetic field. The pair correlations are weakened by t…
Magnetic-field-dependent quasiparticle energy relaxation in mesoscopic wires
A. Anthore, F. Pierre, H. Pothier +1
In order to find out if magnetic impurities can mediate interactions between quasiparticles in metals, we have measured the effect of a magnetic field B on the energy distribution…