The self-actuating InAs nanowire-based nanoelectromechanical Josephson junction

Kretinin, Andrey; Das, Anindya; Shtrikman, Hadas

doi:10.48550/arxiv.1303.1410

Cited by 5 publications

(9 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…19 In addition to those MAR features we systematically observe subgap features, which are not associated with MAR but have some different origin. These features are not related to phonon-induced resonances, 20 and they do not seem to have an electromagnetic origin. They appear on the IVCs as voltage steps, strikingly similar to the voltage steps generated by phase slip centers in superconducting whiskers.…”

Section: Introductionmentioning

confidence: 90%

Charge transport in InAs nanowire Josephson junctions

et al. 2014

View full text Add to dashboard Cite

We present an extensive experimental and theoretical study of the proximity effect in InAs nanowires connected to superconducting electrodes. We fabricate and investigate devices with suspended gate-controlled nanowires and nonsuspended nanowires, with a broad range of lengths and normal-state resistances. We analyze the main features of the current-voltage characteristics: the Josephson current, excess current, and subgap current as functions of length, temperature, magnetic field, and gate voltage, and compare them with theory. The Josephson critical current for a short-length device, L = 30 nm, exhibits a record high magnitude of 800 nA at low temperature that comes close to the theoretically expected value. The critical current in all other devices is typically reduced compared to the theoretical values. The excess current is consistent with the normal resistance data and agrees well with the theory. The subgap current shows a large number of structures; some of them are identified as subharmonic gap structures generated by multiple Andreev reflection. The other structures, detected in both suspended and nonsuspended devices, have the form of voltage steps at voltages that are independent of either the superconducting gap or length of the wire. By varying the gate voltage in suspended devices, we are able to observe a crossover from typical tunneling transport at large negative gate voltage, with suppressed subgap current and negative excess current, to pronounced proximity junction behavior at large positive gate voltage, with enhanced Josephson current and subgap conductance as well as a large positive excess current.

show abstract

Section: Introductionmentioning

confidence: 90%

Charge transport in InAs nanowire Josephson junctions

et al. 2014

View full text Add to dashboard Cite

show abstract

“…It has been theoretically predicted that the AC supercurrent can pump mechanical oscillations in the resonator due to the coupling between electronic and mechanical degrees of freedom [9][10][11][12][13]. Experimental signatures of the excitation of mechanical resonances in vibrating weak-links have been reported in atomic scale oscillators produced in break junctions [14], in torsional SQUID resonators [16] and in suspended nanowires [18]. These early observations testify the potential of current experimental setups to fully explore novel electromechanical effects in the context of superconductivity.…”

Section: Introductionmentioning

confidence: 78%

“…Soon after Josephson's work it was realized that, if the current in the junction is coupled to external AC radiation [2] or internal electromagnetic resonances in the weak link [3,4], new constant-voltage steps in the current-voltage (I-V) characteristic emerge when the AC supercurrent frequency matches a multiple of the intrinsic resonator frequency. Recently, this scenario has been extended, both theoretically and experimentally, to the case in which the weak link itself acts as a mechanical resonator [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. It has been theoretically predicted that the AC supercurrent can pump mechanical oscillations in the resonator due to the coupling between electronic and mechanical degrees of freedom [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Strong mechanically induced effects in DC current-biased suspended Josephson junctions

et al. 2018

View full text Add to dashboard Cite

Superconductivity is a result of quantum coherence at macroscopic scales. Two superconductors separated by a metallic or insulating weak link exhibit the AC Josephson effect -the conversion of a DC voltage bias into an AC supercurrent. This current may be used to activate mechanical oscillations in a suspended weak link. As the DC voltage bias condition is remarkably difficult to achieve in experiments, here we analyse theoretically how the Josephson effect can be exploited to activate and detect mechanical oscillations in the experimentally relevant condition with purely DC current bias. We unveil for the first time how changing the strength of the electromechanical coupling results in two qualitatively different regimes showing dramatic effects of the oscillations on the DC current-voltage characteristic of the device. These include the apperance of Shapirolike plateaux for weak coupling and a sudden mechanically-induced retrapping for strong coupling. Our predictions, measurable in state of the art experimental setups, allow the determination of the frequency and quality factor of the resonator using DC only techniques.

show abstract

“…Other theoretical works investigated the problem of quantum dots coupled to the local vibrations and between two superconductors (S-QD-S) as a Josephson dot coupled to several bosonic modes [125], a suspended carbon-nanotube acting as nanomechanical resonator [66,[126][127][128][129][130][131] or a molecular Josephson junction model [132]. The latter was used to explain the resonance peaks experimentally observed in vibrating Nb nanowires [133,134].…”

Section: Introductionmentioning

confidence: 99%

Charge-vibration interaction effects in normal-superconductor quantum dots

2017

View full text Add to dashboard Cite

We study the quantum transport and the nonequilibrium vibrational states of a quantum dot embedded between a normal-conducting and a superconducting lead with the charge on the quantum dot linearly coupled to a harmonic oscillator of frequency ω. To the leading order in the charge-vibration interaction, we calculate the current and the nonequilibrium phonon occupation by the Keldsyh Green's function technique. We analyze the inelastic, vibration-assisted tunneling processes in the regime ω < , with the superconducting energy gap , and for sharp resonant transmission through the dot. When the energy ε 0 of the dot's level is close to the Fermi energy μ, i.e., |ε 0 − μ| , inelastic vibration-assisted Andreev reflections dominate up to voltage eV . The inelastic quasiparticle tunneling becomes the leading process when the dot's level is close to the superconducting gap |ε 0 − μ| ∼ ± ω. In both cases, the inelastic tunneling processes appear as sharp and prominent peaks-not broadened by temperature-in the current-voltage characteristic and pave the way for inelastic spectroscopy of vibrational modes even at temperatures T ω. We also found that inelastic vibration-assisted Andreev reflections as well as quasiparticle tunneling induce a strong nonequilibrium state of the oscillator. In different ranges on the dot's level, we found that the current produces: (i) ground-state cooling of the oscillator with phonon occupation n 1, (ii) accumulation of energy in the oscillator with n 1, and (iii) a mechanical instability characterized by a negative damping coefficient. We show that ground-state cooling is achieved simultaneously for several modes of different frequencies. Finally, we discuss how the nonequilibrium vibrational state can be readily detected by the asymmetric behavior of the inelastic current peaks with respect to the gate voltage.

show abstract

The self-actuating InAs nanowire-based nanoelectromechanical Josephson junction

Cited by 5 publications

References 18 publications

Charge transport in InAs nanowire Josephson junctions

Charge transport in InAs nanowire Josephson junctions

Strong mechanically induced effects in DC current-biased suspended Josephson junctions

Charge-vibration interaction effects in normal-superconductor quantum dots

Contact Info

Product

Resources

About