OSCAR - Orbital & Spin currents in Cold Atom Rings

• Applicant: Professor Dr. Matteo Rizzi
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Theoretical Condensed Matter Physics
• Term: from 2015 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 277810020

• Final Report Year: 2021

Final Report Abstract

This DFG project allowed us to elucidate some previously overlooked aspects of transport in quasi-1D systems hosting multicomponent quantum fluids of different statistical nature. In particular, we first pointed out and then put on firm grounds a maybe surprising phenomenon as the Drude weight increase by orbital and repulsive interactions in fermionic ladder systems. Moreover, we cornered down a favorable regime for the observation of the so-far elusive collisionless drag for bosonic mixtures, taking further profit from the mesoscopic nature of typical cold atomic setups. The research activity within this project also contributed to further develop numerical methods for periodic boundary conditions (often instrumental for a clean calculation of currents and susceptibilities). We mention here that binary tree tensor networks have allowed us to treat disordered samples with an unprecedented precision for tensor networks algorithms, bridging the pre-existing gap with (sophisticate) Monte Carlo methods. In a spinoff, a time-dependent algorithm for persistent currents in rings have been put forward, too. We plan to deploy these instruments to open-source in the coming future.

Publications

• “Superfluid density and quasi-long-range order in the one-dimensional disordered Bose–Hubbard model”, New J. Phys. 18, 015015 (2016)
  M. Gerster, M. Rizzi, F. Tschirsich, P. Silvi, R. Fazio, S. Montangero
  
• “Continuous matrix product states with periodic boundary conditions and an application to atomtronics”, Phys. Rev. B 95, 045145 (2017)
  D. Draxler, J. Haegeman, F. Verstraete, M. Rizzi
  
• “Tuning the Drude weight of Dirac-Weyl fermions in one-dimensional ring traps”, Phys. Rev. B 96, 241112 (2017)
  M. Bischoff, J. Jünemann, M. Polini, M. Rizzi
  
• “Detecting topology through dynamics in interacting fermionic wires”, Phys. Rev. Res. 2, 033200 (2020)
  A. Haller, P. Massignan, M. Rizzi
  
• “Drude weight increase by orbital and repulsive interactions in fermionic ladders”, Phys. Rev. Res. 2, 023058 (2020);
  A. Haller, M. Rizzi, M. Filippone
  
• “Exploring helical phases of matter in bosonic ladders”, Phys. Rev. Res. 2, 043433 (2020)
  A. Haller, A.S. Matsoukas-Roubeas, Y. Pan, M. Rizzi, M. Burrello
  
• “Collisionless drag for a one-dimensional two-component Bose-Hubbard model”, Phys. Rev. Research 3, L022017 (2021)
  D. Contessi, D. Romito, M. Rizzi, A. Recati