Phonon-Induced Pairing in Quantum Dot Quantum Simulator

Utso Bhattacharya (1, 2) , Tobias Grass (1) , Adrian Bachtold (1) , Maciej Lewenstein (1, 3) , Fabio Pistolesi (4)

1 ICFO - Institut de Ciencies Fotoniques [Castelldefels]
2 MPQ - Max-Planck-Institut für Quantenoptik
3 ICREA - Institució Catalana de Recerca i Estudis Avançats = Catalan Institution for Research and Advanced Studies
4 LOMA - Laboratoire Ondes et Matière d'Aquitaine

Quantum simulations can provide new insights into the physics of strongly correlated electronic systems. A well-studied system, but still open in many regards, is the Hubbard−Holstein Hamiltonian, where electronic repulsion is in competition with attraction generated by the electron−phonon coupling. In this context, we study the behavior of four quantum dots in a suspended carbon nanotube and coupled to its flexural degrees of freedom. The system is described by a Hamiltonian of the Hubbard−Holstein class, where electrons on different sites interact with the same phonon. We find that the system presents a transition from the Mott insulating state to a polaronic state, with the appearance of pairing correlations and the breaking of the translational symmetry. These findings will motivate further theoretical and experimental efforts to employ nanoelectromechanical systems to simulate strongly correlated systems with electron−phonon interactions.

Mots clés: superconductivity; electron−phonon coupling; charge order; nanotubes; Quantum simulation

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Utso Bhattacharya, Tobias Grass, Adrian Bachtold, Maciej Lewenstein, Fabio Pistolesi. Phonon-Induced Pairing in Quantum Dot Quantum Simulator. Nano Letters, 2021, 21 (22), pp.9661 - 9667. ⟨10.1021/acs.nanolett.1c03457⟩. ⟨hal-03464766⟩