arXiv:quant-ph/0511173 · Physical Review A
Tomographic reconstruction of quantum states in N spatial dimensions
Anders S. Mouritzen, Klaus Mølmer
Abstract
Most quantum tomographic methods for massive particles using destructive measurement can only be used for motion in one dimension. We show how to infer the quantum state of a nonrelativistic, $N$-dimensional harmonic oscillator system by simple inverse Radon transforms. We assume a time-independent Hamiltonian for which the dynamics along each coordinate always occurs simultaneously with the others and measurements on all coordinates are performed simultaneously. This is unlike light systems where different modes can be delayed and phase shifted with respect to each other. A requirement of the procedure is that the angular frequencies of the $N$ harmonic potentials be incommensurable. We discuss the information available if the requirement of incommensurability is not fulfilled and also under what conditions the state can be reconstructed from finite-time measurements. As further examples, we consider free particles in $N$ dimensions with periodic boundary conditions and particles in an $N$-dimensional box, where we find a similar condition of incommensurability and finite recurrence time.