Pagano, Guido
Date: Monday, October 23, 2017
Time: 15:00
Place: ETH Zurich, Hönggerberg, HPF G 6
Host: Tilman Esslinger, Manuele Landini
Out-of-equilibrium phenomena in interacting spin chains
Guido Pagano
University of Maryland and NIST, USA
Linear arrays of trapped and laser cooled atomic ions (171Yb+) are a versatile platform for studying strongly correlated many-body quantum systems with long range interactions. By off-resonantly driving motional normal modes with spin-dependent optical dipole forces, we generate tunable long-range spin-spin interactions, which are largely insensitive to the number of ions in the trap. This allows us to study frustrated quantum magnetism in large systems of up to 50 ions with single-site spatial resolution. We achieve a higher degree of control with a tightly-focused laser beam imparting a unique light shift on each ion, which we use for state initialization or to introduce controlled disorder into the system [1].
We use these techniques to study out-of-equilibrium phenomena, including time-crystalline phases and dynamical phase transitions. In particular I will show how time crystals can be realized in a Floquet setting, where the spin system exhibits persistent time-correlations either under Many-body-localized dynamics [2] or in a prethermal regime [3].
Finally, I will also discuss recent experiments exploring a new type of dynamical phase transition in spin systems with long range power law interactions [4,5], and our efforts towards scaling up system sizes to even more trapped ion spins using a cryopumped vacuum chamber.
References:
[1] J. Smith et al., Nat. Phys. 12, 907 (2016)
[2] J. Zhang et al., Nature 543, 217 (2017)
[3] P.Hess et al., in preparation (2017)
[4] Jurcevic et al., PRL 119, 080501 (2017)
[5] J.Zhang, G.Pagano et al., arxiv 1708.01044 (2017)