This node calculates the eigenstates and eigenvalues of the system defined by the Hamiltonian.
The node has the following input:
In the content field, $N_{eigenstates}$ corresponds to the number of eigenstates and eigenvalues that will be calculated and sent to the output. If this value is set to 1, the node calculates the first eigenstate and eigenvalue of the system, which is the ground state.
By default, this value is set at 2 and it can be changed to a higher number to output more than two eigenstates & eigenvalues.
In the example below, the spectrum of a harmonic oscillator is calculated. The content field reads ''5'' which means that the Spectrum node will output the first 5 eigenstates and eigenvalues of this system.