Variational Wave Functions and Their Overlap with the Ground State
- Laboratoire Pierre Aigrain, Departement de Physique, Ecole Normale Superieure, 24 rue Lhomond, F-75005 Paris (France)
- Nanoelectronics Group, Service de Physique de l'Etat Condense, CEA Saclay, 91191 Gif-sur-Yvette cedex (France)
An intrinsic measure of the quality of a variational wave function is given by its overlap with the ground state of the system. We derive a general formula to compute this overlap when quantum dynamics in imaginary time is accessible. The overlap is simply related to the area under the E({tau}) curve, i.e., the energy as a function of imaginary time. This has important applications to, for example, quantum Monte Carlo simulations where the overlap becomes as a simple by-product of routine simulations. As a result, we find that the practical definition of a good variational wave function for quantum Monte Carlo simulations, i.e., fast convergence to the ground state, is equivalent to a good overlap with the actual ground state of the system.
- OSTI ID:
- 20957893
- Journal Information:
- Physical Review Letters, Vol. 99, Issue 3; Other Information: DOI: 10.1103/PhysRevLett.99.030403; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
Similar Records
Generalizing the self-healing diffusion Monte Carlo approach to finite temperature: A path for the optimization of low-energy many-body bases
Variational Monte Carlo calculations of