DMFT-QE Symposium: May 12th

Talk 1:

Solving the dynamics of quantum impurities with a few-body revealing approach

Serge Florens, Néel Institute

Simulating precisely the non-equilibrium dynamics of quantum impurities is generally challenged by a complexity wall at long times. Exploiting time-dependent orbital rotations of matrix product states, we propose a numerically exact algorithm that reveals a hidden few-body and low entanglement structure of the quantum state vector for all times. This method provides drastic improvements both to the accuracy and to the running time of dynamical computations. As an application, we investigate the spatio-temporal formation of the Kondo screening cloud following a quantum quench.

Talk 2:

A rigorous framework for quantum embedding with long-range interactions

George Booth, King’s College London

We will describe a rigorous RPA-based approach to accelerate projection-based quantum embedding with long-range screened interactions. Treating these interactions in an efficient way is (we believe) the biggest conceptual and practical limitation of quantum embedding for ab initio systems. Often, practical embedding approaches rely on uncontrolled approximations and lack systematic improvability. We will describe a two-electron embedding that rigorously folds an effective dynamical interaction into a static model, and detail the steps we are taking to turn this into a practical non-empirical method for ab initio systems. This provides a number of formal advantages over traditional approaches to formulate effective interactions for embedding such as constrained RPA methods.

Scott and Booth, Phys. Rev. Lett. 132, 076401 (2024)
Scott and Booth, Phys. Rev. B. 104, 245114 (2021)
Nusspickel and Booth, Phys. Rev. X 12, 011046 (2022)