gpe.tube

Dynamics in elongated harmonic traps.

See Expansion.md for details.

Attributes

u

Classes

StateGPEdrZ

Effective 1D model for the GPE in harmonic cigars.

Module Contents

u

class StateGPEdrZ(Nxyz, Lxyz, **kw)

Bases: gpe.bec.HOMixin, gpe.bec.StateScaleHO

Effective 1D model for the GPE in harmonic cigars.

This class combines the NPSEQ to derive an effective 1D equation for the dynamics of a harmonically trapped cloud with the scaling solution of Castin and Dum to allow for expansion dynamics.

beta = 2.0

minimize_chemical_potential = False

get_ws(t=None)

Return the trapping frequencies at time t.

Nxyz

Lxyz

init()

Initialize the state.

This method defines the basis positions, momenta, etc. for use later on. We define these here rather than in the constructor __init__() so that the user can change them later and the reinitialize the state. We also call this function from the pre_evolve_hook() so that it is called before any evolution takes place. For this reason, we should not modify the state here.

get_sigma2s(abs_Phi2=None)

Return (sigma2x, sigma2y).

get_central_density(TF=False)

Return the physical density (3D) along the central axis of the trap.

Parameters:

TF (bool) – If True, then assume the transverse cloud is a TF profile (otherwise use the internal Gaussian anzatz.)

get_V_GPU()

Return the complete potential V - internal and external.

get_energy_density()

Return the energy density.

get_n_TF(V_TF, V_ext=None, g=None)

Return the Thomas Fermi density profile n_1D from mu.

Parameters:

V_TF (float) – Value of V(x_TF) where the density should vanish in the TF limit.

get_mu_from_V_TF(V_TF)

Return the Thomas Fermi chemical potential from V_TF.

Parameters:

V_TF (float) – External potential at the Thomas Fermi “radius”. (The external potential is evaluated at this position and this is used to get mu.)

get_V_TF_from_mu(mu)

Return V_TF from the chemical potential mu.

Parameters:

mu (float) – Physical chemical potential (i.e. what you would pass to the minimizer).