• Séminaire LPMMC
• Personne à contacter : Denis Basko ()
• G 421

Résumé : The problem of the temperature dependence of the superfluid stiffness Θ in strongly disordered pseudo-gapped superconductors is relevant for the search of superconducting superinductors – the devices much wanted for several fields of modern quantum technology. The key theoretical challenge is twofold: 1) one has to consistently describe the substantially inhomogeneous superconducting state, known to exist in such superconductors [1,2] even moderately far from the superconductor-insulator transition, and 2) after that one has to calculate the macroscopic electromagnetic response of the resulting disorder media, a challenging problem in its own right. In this talk, we address both of these problems and derive an analytical equation that describes the temperature variation of the superfluid stiffness. At low temperatures, the temperature variation of the superfluid stiffness is close to a power law, Θ(T = 0) - Θ(T) ∝ T^b, where the exponent b ~ 2-3 is disorder-dependent. This result is in qualitative agreement with the experimental results obtained recently by Thibault Charpentier from the Néel Institute.

[1] B. Sacépé, T. Dubouchet, C. Chapelier, M. Sanquer, M. Ovadia, D. Shahar, M.V. Feigel'man and L.B. Ioffe, "Localization of preformed Cooper pairs in disordered superconductors", Nature Physics 7, 3 (2011), pp. 239–244.
[2] A.V. Khvalyuk and M.V. Feigel'man, "Distribution of the order parameter in strongly disordered superconductors: An analytic theory", Phys. Rev. B 104 (2021), pp. 224505.

Liens :LPMMC

• Séminaire LPMMC
• Personne à contacter : Vincent Rossetto ()
• G 421

Résumé : We identify a mapping between two-dimensional (2D) electron transport in a minimally twisted graphene bilayer and a 1D quantum walk, where one spatial dimension plays the role of time. In this mapping a magnetic field B perpendicular to the bilayer maps onto an electric field. Bloch oscillations due to the periodic motion in a 1D Bloch band can then be observed in purely DC transport as magnetoconductance oscillations with periodicity set by the Bloch frequency. Ref : Phys. Rev. B 105, L241408 (2022)

Liens :

• Séminaire interne LPMMC
• Personne à contacter : Léonie Canet ()
• G 421

Liens :LPMMC

• Séminaire LPMMC
• Personne à contacter : Cécile Repellin ()
• G 421

Liens :

• Séminaire interne LPMMC
• Personne à contacter : Denis Basko ()
• G 421

Liens :

• Séminaire interne LPMMC
• Personne à contacter : Benoît Vermersch ()
• G 421

Liens :LPMMC

• Séminaire interne LPMMC
• Personne à contacter : Vincent Rossetto ()
• G 421

Liens :LPMMC

• Séminaire théorie
• Personne à contacter : Adolfo Grushin ()
• G 421

Liens :

• Séminaire théorie
• Personne à contacter : Adolfo Grushin ()
• G 421

Liens :