Phases and dynamics of correlated systems: Charge order in the cuprate superconductors and dynamic phase transitions
The first part of the talk addresses the physics of the cuprate superconductors. I will review some recent experimental evidence for incommensurate charge order in the pseudogap phase of various compounds. Motivated by these observations, we performed a number of complementary computations to analyze charge-neutral, spin-singlet ordering in metals on the square lattice taking into account correlation effects. We examined ordering with and without time-reversal symmetry, with arbitrary wave-vector and tunable form factor. Depending on the model parameters, we find a variety of different charge ordering possibilities including ones with wave-vectors parallel to the lattice generators and a d-wave form factor. The relation of these findings to the experiments is discussed. The second part of the talk deals with the non-equilibrium dynamics of spontaneous symmetry breaking for interacting fermions motivated by experiments with ultracold atoms. Within a Keldysh perturbation theory we compute single and two-particle dynamics of fermions on a lattice after a fast interaction ramp close to a magnetic instability. This allows us to analyze the interplay of thermalization processes with the growth of unstable magnetic modes and to establish a dynamic phase diagram.
Subscribe to A Quantum Bit
Quantum physics began with revolutionary discoveries in the early twentieth century and continues to be central in today’s physics research. Learn about quantum physics, bit by bit. From definitions to the latest research, this is your portal. Subscribe to receive regular emails from the quantum world. Previous Issues...
Sign Up Now
Sign up to receive A Quantum Bit in your email!