Patent ID: 6924501

Claim:
A quantum logic gate utilizing an electronic state of a semiconductor quantum structure comprising: a first semiconductor quantum well structure as a control quantum bit, said first semiconductor quantum well structure having a first width; a second semiconductor quantum well structure as a target quantum bit having a second width which differs from the first width of the first semiconductor quantum well structure; means for generating one exciton with self polarization in each of the first and second semiconductor quantum well structures; and means for inverting the target quantum bit from |1> state to |0> state or from |0> state to |1> state only when the control quantum bit is in the |1> state by irradiating an electromagnetic wave corresponding to a shifted energy difference to the second semiconductor quantum well structure, where the |0> state is a state in which the exciton is not excited and the |1> state is a state in which the exciton is excited for the first and second semiconductor well structures, wherein the shifted energy difference is shifted by an amount of an inter-polarization (dipole-dipole) interaction between the excitons which occurs only when the exciton is generated simultaneously one by one both in the first and second semiconductor quantum well structures, from an energy difference between the |0> state and the |1> state without the inter-polarization (dipole-dipole) interaction.