seemps.analysis.derivatives.fourier_derivative#
- seemps.analysis.derivatives.fourier_derivative(psi: MPS | MPSSum, order: int, interval: QuantizedInterval | tuple[float, float, int]) MPS | MPSSum[source]#
Nth-order derivative via Quantum Fourier Transform.
Compute the order-th spatial derivative of a quantum state psi defined on a uniform grid of length L, using the QFT and momentum-space multiplication.
- Parameters:
- psi
MPSorMPSSum Quantum state in position representation
- order
int Order of the derivative
- interval: QuantizedInterval | IntervalTuple
The interval over which the function is defined.
- psi
- Returns:
- d_psi
MPSorMPSSum Quantum state encoding the derivative
- d_psi