Bec2hpc: A Hpc Spectral Solver For Nonlinear Schrodinger And Rotating Gross-Pitaevskii Equations. Stationary States Computation

We present BEC2HPC which is a parallel HPC spectral solver for computing the ground states of the nonlinear Schrodinger equation and the Gross-Pitaevskii equation (GPE) modeling rotating Bose-Einstein condensates (BEC). Considering a standard pseudo-spectral discretization based on Fast Fourier Transforms (FFTs), the method consists in finding the numerical solution of the energy functional minimization problem under normalization constraint by using a preconditioned nonlinear conjugate gradient method. We present some numerical simulations and scalability results for the 2D and 3D problems to obtain the stationary states of BEC with fast rotation and large nonlinearities. The code takes advantage of existing HPC libraries and can itself be leveraged to implement other numerical methods like e.g. for the dynamics of BECs. (C) 2021 Elsevier B.V. All rights reserved.