Browsing by Subject "Hamiltonians"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Observation of parity-time symmetry breaking transitions in a dissipative Floquet system of ultracold atoms
    (Springer Nature, 2019-02-20) Li, Jiaming; Harter, Andrew K.; Liu, Ji; de Melo, Leonardo; Joglekar, Yogesh N.; Luo, Le; Physics, School of Science
    Open physical systems with balanced loss and gain, described by non-Hermitian parity-time [Formula: see text] reflection symmetric Hamiltonians, exhibit a transition which could engender modes that exponentially decay or grow with time, and thus spontaneously breaks the [Formula: see text]-symmetry. Such [Formula: see text]-symmetry-breaking transitions have attracted many interests because of their extraordinary behaviors and functionalities absent in closed systems. Here we report on the observation of [Formula: see text]-symmetry-breaking transitions by engineering time-periodic dissipation and coupling, which are realized through state-dependent atom loss in an optical dipole trap of ultracold 6Li atoms. Comparing with a single transition appearing for static dissipation, the time-periodic counterpart undergoes [Formula: see text]-symmetry breaking and restoring transitions at vanishingly small dissipation strength in both single and multiphoton transition domains, revealing rich phase structures associated to a Floquet open system. The results enable ultracold atoms to be a versatile tool for studying [Formula: see text]-symmetric quantum systems.
  • Thumbnail Image
    Item
    Observation of slowly decaying eigenmodes without exceptional points in Floquet dissipative synthetic circuits
    (Springer Nature, 2018-12-03) León-Montiel, Roberto de J.; Quiroz-Juárez, Mario A.; Domínguez-Juárez, Jorge L.; Quintero-Torres, Rafael; Aragón, José L.; Harter, Andrew K.; Joglekar, Yogesh N.; Physics, School of Science
    Parity-time symmetric systems allow one to study new types of Hamiltonians which could have potential impact on our understanding of nonlinear physics. The authors investigate the energy stored in an electronic Floquet system and demonstrate that such a setup can be used to study the dynamics of dissipative parity-time symmetric systems.