Quantum steps in hysteresis loops

Chandan Kumar Mondal, SP Bhattacharyya

Chih-Chun Chien, Mekena Metcalf, Chen-Yen Lai

Michael Thorwart, Peter Reimann, Peter Jung +1 more

Michael Thorwart, Peter Reimann, Peter Jung

We are studying bistable quantum systems coupled to a thermal environment and driven by a strong external force. Thermal and quantum effects on the switching hysteresis are studied numerically by evaluating a time-dependent real-time double path-integral with the recently developed iterative tensor multiplication scheme for the Quasi-adiabatic path-integral propagator method. For temperatures below the quantum-classical crossover temperature, the response of the system exhibits steps for slow external driving. We show that these steps are due to dissipative resonant tunneling and appear in the vicinity of avoided level-crossings of the spectrum of the undamped Hamiltonian. We discuss possible relations to the recently discovered hysteresis steps in organic high-spin molecules.

Michael Thorwart, Peter Reimann, Peter Jung +1 more

Abstract We numerically demonstrate that the response of a damped quantum particle in a bistable potential to a strong time-dependent force exhibits steps at some specific values of the force. They can be associated with avoided level crossings in the spectrum of the undamped and parametrically tilted, static system and are accompanied by a multiresonance structure of the relaxation rate.

Dafna Bortman, Amiram Ron