US Patent 7230266 - Oscillation readout for quantum computing

http://www.freepatentsonline.com/7230266.html

D-Wave is a company that focuses on superconducting electronics to achieve quantum computing and currently has the largest U.S. patent portfolio in this area. Although superconducting materials can be difficult to work with if the development of a quantum computer is achieved it will open up the possibility of more exact modeling and simulation of stochastic phenomena which can be applied to economic and weather forecasting. This latest patent focuses on a reading method of a qubit using the frequency response of a quantum system. Claim 1 reads:

1. A method for determining whether a first state of a quantum system is occupied, the method comprising: (A) applying a signal to the quantum system at a frequency that corresponds to an energy level separation between said first state and a second state of said quantum system, wherein (i) said quantum system produces a readout frequency when said first state is occupied at a time when said signal is applied, and (ii) said quantum system does not produce said readout frequency when said first state is not occupied at the time when said signal is applied; and (B) measuring a property of a measurement resonator that is conditionally coupled to the quantum system when said quantum system produces said readout frequency, thereby determining whether said first state of said quantum system is occupied.