Dissipationless states in dissipative systems

Benjamin Fain

Masaaki Tokieda, Shimpei Endo

We analytically study quantum dissipative dynamics described by the Caldirola-Kanai model with inter-particle interactions. We have found that the dissipative quantum dynamics of the Caldirola-Kanai model can be exactly mapped to a dissipationless quantum dynamics under a negative external harmonic potential, even when the particles are strongly interacting. In particular, we show that the mapping is valid for the unitary Fermi gas, which is relevant for cold atoms and nuclear matters.

Sushanta Dattagupta, Sanjay Puri

Klaus Voelker

Sebastian Deffner, Christopher Jarzynski, Adolfo del Campo

A natural nonequilibrium process that takes a system from one equilibrium state to another in a short time always involves dissipation. But, it's actually possible in quantum control to design and implement dissipationless ``shortcuts'' for quantum systems. Scientists add a few concrete practical tools for achieving this goal.

José A. Hoyos, Thomas Vojta

We study the effects of Ohmic, super-Ohmic, and sub-Ohmic dissipation on the zero-temperature quantum phase transition in the random transverse-field Ising chain by means of an (asymptotically exact) analytical strong-disorder renormalization-group approach. We find that Ohmic damping destabilizes the infinite-randomness critical point and the associated quantum Griffiths singularities of the dissipationless system. The quantum dynamics of large magnetic clusters freezes completely, which destroys the sharp phase transition by smearing. The effects of sub-Ohmic dissipation are similar and also lead to a smeared transition. In contrast, super-Ohmic damping is an irrelevant perturbation; the critical behavior is thus identical to that of the dissipationless system. We discuss the resulting phase diagrams, the behavior of various observables, and the implications to higher dimensions and experiments.