Charging effects and quantum coherence in regular Josephson junction arrays

Geerligs, L.J.; Peters, Mathijs; Groot, L. E. M. de; Verbruggen, A. H.; Mooij, J. E.

doi:10.1103/physrevlett.63.326

Cited by 229 publications

(124 citation statements)

References 39 publications

Supporting

Mentioning

116

Contrasting

Order By: Relevance

“…For example, the current I and voltage V are interchanged across the SIT, so that the I-V curve in the superconducting phase is similar in shape to the V-I curve in the insulating state. Such dual I-V characteristics have been observed in Josephson junction arrays and disordered thin films 3,22,23 .…”

Section: Mr In the Superconducting Statementioning

confidence: 83%

“…Nevertheless, measurements of the current-dependent differential resistance (Methods) indicate that the transition is to a weakly insulating state where regions of superconductivity get increasingly isolated from one another as V g is decreased. Thus, it makes sense to model our sample as a granular superconductor consisting of a network of superconducting islands whose phase is coupled through the Josephson effect, parametrized by the Josephson energy E J and a Coulomb charging energy E c , which is associated with the energy cost of adding a Cooper pair to an island 3,18 . (For a random network of islands, these quantities are averages over the network.)…”

Section: Mr In the Superconducting Statementioning

confidence: 99%

“…T he two-dimensional superconductor to insulator transition (SIT) has been studied extensively [1][2][3] , as experimentally it is one of the few easily accessible manifestations of a quantum phase transition. The two-dimensional electron gas formed at the LaAlO 3 /SrTiO 3 (LAO-STO) interface [4][5][6] has been shown to undergo a SIT as the density of the carriers is tuned [7][8][9] .…”

mentioning

confidence: 99%

See 2 more Smart Citations

Evidence for charge–vortex duality at the LaAlO3/SrTiO3 interface

et al. 2012

View full text Add to dashboard Cite

The concept of duality has proved extremely powerful in extending our understanding in many areas of physics. Charge-vortex duality has been proposed as a model to understand the superconductor to insulator transition in disordered thin films and Josephson junction arrays. In this model, on the superconducting side, one has delocalized Cooper pairs but localized vortices; while on the insulating side, one has localized Cooper pairs but mobile vortices. Here we show a new experimental manifestation of this duality in the electron gas that forms at the interface between LaAlo 3 and srTio 3 . The effect is due to the motion of vortices generated by the magnetization dynamics of the ferromagnet that also forms at the same interface, which results in an increase in resistance on the superconducting side of the transition, but an increase in conductance on the insulating side.

show abstract

Section: Mr In the Superconducting Statementioning

confidence: 83%

Section: Mr In the Superconducting Statementioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Evidence for charge–vortex duality at the LaAlO3/SrTiO3 interface

et al. 2012

View full text Add to dashboard Cite

show abstract

“…When charging effects due to the small capacitance of the grains or junctions dominate, strong quantum fluctuations of the phase of the superconducting order parameter may drive the system into an insulating phase at zero temperature, leading to a superconductor-to-insulator transition as a function of charging energy or an external magnetic field. In two dimensions, the universality class of these transitions have already been investigated in detail numerically, 6 both in relation to experiments 3,4 and theoretical predictions. [7][8][9] Nevertheless, there are also remarkable quantum phase transition scenarios 10 that can take place in a Josephson-junction ladder in a magnetic field as in Fig.…”

mentioning

confidence: 99%

“…[1][2][3][4][5] Such arrays can currently be fabricated in any desired geometry both in one and two dimensions 4,5 with well-controlled parameters. When charging effects due to the small capacitance of the grains or junctions dominate, strong quantum fluctuations of the phase of the superconducting order parameter may drive the system into an insulating phase at zero temperature, leading to a superconductor-to-insulator transition as a function of charging energy or an external magnetic field.…”

mentioning

confidence: 99%

Field-induced superconductor-to-insulator transition in Josephson-junction ladders

Granato

2005

Phys. Rev. B

View full text Add to dashboard Cite

The superconductor-to-insulator transition is studied in a self-charging model for a ladder of Josephson junctions in the presence of an external magnetic field. Path integral Monte Carlo simulations of the equivalent ͑1+1͒-dimensional classical model are used to study the phase diagram and critical behavior. In addition to a superconducting ͑vortex-free͒ phase, a vortex phase can also occur for an increasing magnetic field and small charging energy. It is found that an intervening insulating phase separates the superconducting from the vortex phases. Surprisingly, a finite-size scaling analysis shows that the field-induced superconducting-to-insulator transition is in the KT universality class, even though the external field breaks time-reversal symmetry. DOI: 10.1103/PhysRevB.72.104521 PACS number͑s͒: 74.40.ϩk, 74.81.Fa, 73.43.Nq, 74.25.Qt Superconductor-to-insulator transitions in Josephson junction arrays have attracted considerable interest. 1-5 Such arrays can currently be fabricated in any desired geometry both in one and two dimensions 4,5 with well-controlled parameters. When charging effects due to the small capacitance of the grains or junctions dominate, strong quantum fluctuations of the phase of the superconducting order parameter may drive the system into an insulating phase at zero temperature, leading to a superconductor-to-insulator transition as a function of charging energy or an external magnetic field. In two dimensions, the universality class of these transitions have already been investigated in detail numerically, 6 both in relation to experiments 3,4 and theoretical predictions. 7-9 Nevertheless, there are also remarkable quantum phase transition scenarios 10 that can take place in a Josephson-junction ladder in a magnetic field as in Fig. 1 which have not been investigated experimentally or numerically. Interestingly, a Josephson-junction ladder provides the simplest onedimensional version of the array allowing the study of commensurability effects due to the flux lattice 10-13 or charge frustration, 14 in the presence of quantum fluctuations.An important aspect of the Josephson-junction ladder in Fig. 1 is the approximate relation to the quantum sineGordon model, 15 as first shown by Kardar. 10 For an increasing magnetic field, there is a transition from a ͑vortex-free͒ superconducting phase to a vortex phase, where flux penetrates the ladder, in the absence of quantum fluctuations. This transition is the analog of the commensurateincommensurate transition 16 described by the sine-Gordon model. For small fields, the phases in different branches of the ladder are locked to each other while in the vortex state exponentially interacting kinks ͑vortices͒ appear that unlock the phases leading to a one-dimensional vortex lattice. The inclusion of quantum fluctuations due to charging effects leads to the interesting prediction that an insulating phase should occur in the vicinity of this transition and therefore a direct transition from the ͑vortex-free͒ superconducting phase to the vort...

show abstract

Modulations in Superconductors: Probes of Underlying Physics

et al. 2023

View full text Add to dashboard Cite

development of various modulations techniques, breakthroughs in quantum materials are achieved, such as the quantum anomalous Hall effect (AHE) in topological insulators, [1][2][3][4] gate-tuned roomtemperature ferromagnetism in 2D van der Waals materials, [5][6][7][8] and emergent magnetic monopoles in artificial spin ice. [9] Especially, as the quantum materials of particular interest with zero dissipation, superconductors have been intensively studied with advanced modulations, aiming to reveal a plethora of emergent phenomena in condensed matter physics, such as superconductor-to-insulator transitions (SIT), [10][11][12] intermediate bosonic metallic state, [13] Bose-Einstein condensation (BEC)-Bardeen-Cooper-Schrieffer (BCS) crossover, [14,15] and intertwined orders, [16][17][18] as well as to develop applications in quantum computing [19][20][21] and ultrasensitive detections. [22][23][24] The superconductivity composes of two ingredients, including the Cooper pairs, each formed by two electrons, and phase coherence among Cooper pairs. [25] Superconductors such as metals and alloys are in the weak-coupling regime, which is well understood by BCS theory. [26,27] However, the later discovered superconductors, including cuprates, iron-based superconductors, and heavy-fermion superconductors, are strongly correlated systems, where a widely accepted microscopic mechanism yet remains absent. Therefore, various modulations have been utilized for the ultimate understanding of these superconductors and routines for room temperature superconductivity. Traditional modulations, such as elemental substitution, annealing, and polarization-induced gating are usually accompanied by some severe problems, including discontinuity, disorders, and limited ranges. Recently, state-of-the-art techniques have been developed with improved convenience, increased capability, and unprecedented dimensionalities, enabling more thorough investigations of unconventional superconductors.As a manifestation, we take some examples discussed in this review in advance. The carrier density can be tuned more conveniently and continuously. The techniques of ionic field-effect transistor (iFET) and electric double-layer transistor (EDLT) surpass conventional methods limited by solid solubility or dielectric breakdown, which enables the more precise phase diagram and detailed scaling analysis at the quantum phaseThe importance of modulations is elevated to an unprecedented level, due to the delicate conditions required to bring out exotic phenomena in quantum materials, such as topological materials, magnetic materials, and superconductors. Recently, state-of-the-art modulation techniques in material science, such as electric-double-layer transistor, piezoelectric-based strain apparatus, angle twisting, and nanofabrication, have been utilized in superconductors. They not only efficiently increase the tuning capability to the broader ranges but also extend the tuning dimensionality to unprecedented degrees of freedom, including quantum fluctuations of...

show abstract

Charging effects and quantum coherence in regular Josephson junction arrays

Cited by 229 publications

References 39 publications

Evidence for charge–vortex duality at the LaAlO3/SrTiO3 interface

Evidence for charge–vortex duality at the LaAlO3/SrTiO3 interface

Field-induced superconductor-to-insulator transition in Josephson-junction ladders

Modulations in Superconductors: Probes of Underlying Physics

Contact Info

Product

Resources

About