schr.qm.wavefunction module

Wavefunction utilities for quantum mechanics.

schr.qm.wavefunction.gaussian_wavepacket(x: ~jax.Array | tuple[~jax.Array, ...], x0: float | tuple[float, ...], p0: float | tuple[float, ...], sigma: float, hbar: float = 1.0, dtype: ~numpy.dtype = <class 'jax.numpy.complex64'>) Array[source]

Create Gaussian wave packet.

\[\psi(\mathbf{r}) = (2\pi\sigma^2)^{-d/4} \exp\left[-\frac{(\mathbf{r}-\mathbf{r}_0)^2}{4\sigma^2}\right] \exp\left[\frac{i\mathbf{p}_0\cdot(\mathbf{r}-\mathbf{r}_0)}{\hbar}\right]\]

where \(d\) is the dimensionality.

Parameters:
  • x – Spatial grid. 1D: array (nx,). 2D: tuple (X, Y) of shape (ny, nx). 3D: tuple (X, Y, Z).

  • x0 – Center position (a.u.). Scalar for 1D, tuple for 2D/3D.

  • p0 – Initial momentum (a.u.). Scalar for 1D, tuple for 2D/3D.

  • sigma – Width parameter (a.u.).

  • hbar – Reduced Planck constant (default: 1.0 a.u.).

  • dtype – JAX dtype (default: complex64).

Returns:

Normalized Gaussian wave packet.

Raises:

ValueError – If dimensions are inconsistent.

schr.qm.wavefunction.normalize(psi: Array, dx: float) Array[source]

Normalize wavefunction to \(\int|\psi|^2 dV = 1\).

Parameters:
  • psi – Wavefunction.

  • dx – Grid spacing (a.u., uniform in all dimensions).

Returns:

Normalized wavefunction.

schr.qm.wavefunction.plane_wave(x: ~jax.Array | tuple[~jax.Array, ...], k: float | tuple[float, ...], dtype: ~numpy.dtype = <class 'jax.numpy.complex64'>) Array[source]

Create plane wave \(\exp(i\mathbf{k}\cdot\mathbf{r})\).

Parameters:
  • x – Spatial grid (1D array or tuple of arrays).

  • k – Wave vector (a.u.). Scalar for 1D, tuple for 2D/3D.

  • dtype – JAX dtype (default: complex64).

Returns:

Plane wave (not normalized).

Raises:

ValueError – If dimensions are inconsistent.

schr.qm.wavefunction.probability_current_1d(psi: Array, dx: float, mass: float = 1.0, hbar: float = 1.0) Array[source]

Compute probability current density in 1D.

\[j = \frac{\hbar}{m} \text{Im}\left[\psi^* \frac{\partial\psi}{\partial x}\right]\]
Parameters:
  • psi – Wavefunction (1D).

  • dx – Grid spacing (a.u.).

  • mass – Particle mass (default: 1.0 a.u.).

  • hbar – Reduced Planck constant (default: 1.0 a.u.).

Returns:

Probability current density.

schr.qm.wavefunction.probability_density(psi: Array) Array[source]

Compute probability density \(|\psi|^2\).

Parameters:

psi – Wavefunction.

Returns:

Probability density.