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Arbel Haim | The Racah Institute of Physics

Arbel Haim

Date: 
Thu, 28/11/201912:00-13:15

Title: Variational-Correlations Approach to Quantum Many-Body Physics
Abstract: I will present a variational method for studying the ground state of a quantum many-body Hamiltonian, that treats the correlation functions as variational parameters. This numerical approach is based on approximating the positivity of the density matrix in a controlled manner, and allows for obtaining the (approximate) ground state in polynomial time. Unlike the conventional variational principle which provides an upper bound on the ground-state energy, in this approach one obtains a lower bound on the ground-state energy. I will demonstrate the method on several one-dimensional spin 1/2 Hamiltonians. Possible extensions of the method will be discussed.