MEASUREMENTS ON TRAPPED LASER-COOLED IONS USING QUANTUM COMPUTATIONS

We show that a series of quantum computations involving an isolated N- quantum-bit ion register can be used to make an approximate quantum no ndemolition measurement of the number state distribution of a collecti ve vibrational mode. A unitary transformation is applied to the Fourie r transformed state of the ion register to copy the vibrational statis tics to the electronic mode, and the number state distribution is then measured in the electronic number state basis using the quantum jumps technique.