Make a matrix representation of a singular quadrature operator in the Fock space.

Since the bosonic operators lie in an infinite Fock space, a truncation value needs to be provide so that a sparse matrix of finite size can be returned.

n_modes int

Number of modes in the system Hilbert space.

mode int

The mode the ladder operator targets.

quadrature str

'q' for the canonical position operator, 'p' for the canonical moment]um operator.

hbar float

the value of hbar to use in the definition of the canonical commutation relation [q_i, pj] = \delta{ij} i hbar.

trunc int

The size at which the Fock space should be truncated when returning the matrix representing the ladder operator.

The corresponding trunc x trunc Scipy sparse matrix.