2021/11/06 by Kazuaki Takasan, Takasan, Kazuaki, Masaki Tezuka +1
Economics, Econometrics and Finance · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Complex Systems and Time Series Analysis #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum Gases (cond-mat.quant-gas) #Quantum Physics (quant-ph) #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2111.03857
openalex publication_date 2021/11/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the magnetism in tilted fermionic Mott insulators. With a small tilt, the fermions are still localized and form a Mott-insulating state, where the localized spins interact via antiferromagnetic exchange coupling. While the localized state is naively expected to be broken with a large tilt, in fact, the fermions are still localized under a large tilt due to the Wannier-Stark localization and it can be regarded as a localized spin system. We find that the sign of the exchange coupling is changed and the ferromagnetic interaction is realized under the large tilt. To show this, we employ perturbation theory and real-time numerical simulation of the fermionic Hubbard chain. Our simulation exhibits that it is possible to effectively control the speed and time direction of the dynamics by changing the size of the tilt, which may be useful for experimentally measuring out-of-time-ordered correlators. Finally, we discuss experimental platforms, such as ultracold atoms in an optical lattice, to observe these phenomena.