Computational Studies of Strongly Interacting Ultracold Atoms
Abstract
We develop and apply computational methods to investigate correlation effects in atomic and molecular systems, and in optical lattice systems. Problems from both classes are studied synergistically. We quantified effects of many-body correlations in trapped atomic Bose gases; developed auxiliary-field quantum Monte Carlo method for Bosons and fermions whose computational cost scales as N^3-N^4 with system size; benchmarked the method in molecular systems using Gaussian basis functions; demonstrated that its accuracy is comparable to the preeminent quantum chemistry coupled-cluster method CCSD(T) for systems near equilibrium geometry, and better than the latter when bonds are stretched or broken; developed methods to correct for finite-size errors to drastically improve the efficiency of many-body simulations by reaching larger and more realistic system sizes; formulated an approach to eliminate spin contamination in auxiliary-field calculations; examined spin-density waves states in simple models of metallic systems; showed the existence of incommensurate spin-density waves in two-dimensional optical lattices with positive scattering lengths.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2010
- Accession Number
- ADA532710
Entities
People
- Shiwei Zhang
Organizations
- College of William & Mary