Nonequilibrium Dynamics Across an Impurity Quantum Critical Point

Abstract

Whether a small quantum mechanical system is able to equilibrate with its environment once an external local perturbation drives it out of thermal equilibrium is a central question which cuts across many different fields of science. Here we consider such a problem for a correlated quantum impurity coupled to a fermionic reservoir and driven out of equilibrium by local quantum quenches such as those recently realized in optical absorption experiments on single quantum dots. We argue that equilibration in this problem is deeply connected to the occurrence of Kondo Effect at low energy and that a highly non trivial dynamical behavior may emerge whenever a local quantum critical point intrudes between a conventional Kondo screened phase and a Kondo unscreened one. We discuss this issue in the context of the Anderson Impurity model coupled to a pseudo-gap reservoir by using a correlated time dependent variational wave function that is able to qualitatively describe this physics.

4+3 pages, 3 figures

References in corpus (16)

• The numerical renormalization group method for quantum impurity systems
• Real-time dynamics in Quantum Impurity Systems: A Time-dependent Numerical Renormalization Group Approach
• Quantum phase transition in a single-molecule quantum dot
• Spin Precession and Real Time Dynamics in the Kondo Model: A Time-Dependent Numerical Renormalization-Group Study
• Time-Dependent Mean Field Theory for Quench Dynamics in correlated electron systems
• Universal Scaling in Non-equilibrium Transport Through a Single-Channel Kondo Dot
• Equilibrium and non-equilibrium dynamics of the sub-ohmic spin-boson model
• Phase transitions in the pseudogap Anderson and Kondo models: Critical dimensions, renormalization group, and local-moment criticality
• Critical and strong-coupling phases in one- and two-bath spin-boson models
• Upper-critical dimension in a quantum impurity model: Critical theory of the asymmetric pseudogap Kondo problem
• Wilson chains are not thermal reservoirs
• Anderson Orthogonality in the Dynamics After a Local Quantum Quench
• Absorption and Emission in quantum dots: Fermi surface effects of Anderson excitons
• Quantum criticality of the sub-ohmic spin-boson model
• Quantum quenches and driven dynamics in a single-molecule device
• Sub-ohmic two-level system representation of the Kondo effect

Cited by in corpus (10)

• Time-Dependent Numerical Renormalization Group Method for Multiple Quenches: Application to General Pulses and Periodic Driving
• Pseudogap Anderson impurity model out of equilibrium: A master equation tensor network approach
• Steady-state dynamics and effective temperatures of quantum criticality in an open system
• Impurity model for non-equilibrium steady states
• Time-dependent ghost-Gutzwiller non-equilibrium dynamics
• Transient phases and dynamical transitions in the post quench evolution of the generalized Bose-Anderson model
• Dynamics of the impurity screening cloud following quantum quenches of the Resonant Level Model
• Real-time dynamics induced by quenches across the quantum critical points in gapless Fermi systems with a magnetic impurity
• Ballistic Entanglement Cloud after a Boundary Quench
• Dissipative Kondo physics in the Anderson Impurity Model with two-body losses