Systems and methods for controlled quantum information processing with a trans-radix basis component

1. A trans-radix quantum circuit, comprising:

a quantum circuit element implementing a Chrestenson transform matrix, wherein the quantum circuit element is adapted to operate as a trans-radix two qubit quantum circuit element, wherein the two qubits include a first radix-2 qubit and a second radix-2 qubit.

2. The trans-radix quantum circuit of claim 1 , further comprising:

one or more radix-2 quantum circuit elements coupled to the quantum circuit element, wherein the trans-radix quantum circuit is adapted to operate as a controlled quantum circuit.

3. The trans-radix quantum circuit of claim 2 , wherein the one or more radix-2 quantum circuit elements include a radix-2 quantum circuit element implementing a Hadamard transform matrix, and the trans-radix quantum circuit is adapted to operate as a radix-2 controlled-S quantum circuit element.

4. The trans-radix quantum circuit of claim 3 , wherein the radix-2 quantum circuit element is applied to the first qubit before the first qubit is provided to the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element.

5. The trans-radix quantum circuit of claim 4 , wherein the radix-2 quantum circuit element is applied to the first qubit after the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the first qubit.

6. The trans-radix quantum circuit of claim 2 , wherein the one or more radix-2 quantum circuit elements include a radix-2 quantum circuit element implementing a Hadamard transform matrix, and the trans-radix quantum circuit is adapted to operate as a radix-2 controlled-Z quantum circuit element.

7. The trans-radix quantum circuit of claim 6 , wherein the radix-2 quantum circuit element is applied to the first qubit before the first qubit is provided to the quantum circuit element implementing the Chrestenson transform matrix adapted to operate as the trans-radix two qubit quantum circuit element for the first time.

8. The trans-radix quantum circuit of claim 7 , wherein the radix-2 quantum circuit element is applied to the first qubit after the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the first qubit for the first time and before the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the first qubit for the second time.

9. The trans-radix quantum circuit of claim 8 , wherein the radix-2 quantum circuit element is applied to the second qubit before the second qubit is provided to the quantum circuit element implementing the Chrestenson transform matrix adapted to operate as the trans-radix two qubit quantum circuit element for the second time.

10. The trans-radix quantum circuit of claim 9 , wherein the radix-2 quantum circuit element is applied to the second qubit after the second qubit after the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the second qubit for the second time.

11. The trans-radix quantum circuit of claim 2 , wherein the one more radix-2 quantum circuit elements include a radix-2 quantum circuit element implementing a Hadamard transform matrix, and the trans-radix quantum circuit is adapted to operate as a radix-2 controlled-X quantum circuit element.

12. The trans-radix quantum circuit of claim 11 , wherein the radix-2 quantum circuit element is applied to the first qubit after the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the first qubit for the first time and before the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the first qubit for the second time and the radix-2 quantum circuit element is applied to the second qubit after the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the second qubit for the first time and before the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the second qubit for the second time.

13. The trans-radix quantum circuit of claim 12 , wherein the radix-2 quantum circuit element is applied to the first qubit after the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the first qubit for the second time and the radix-2 quantum circuit element is applied to the second qubit after the quantum circuit element adapted to operate as the trans-radix two qubit quantum circuit element is applied to the second qubit for the second time.

14. The trans-radix quantum circuit of claim 1 , wherein the quantum circuit element implementing the Chrestenson transform matrix is implemented in photonics.

15. The trans-radix quantum circuit of claim 14 , wherein the quantum circuit element is an optical four-port directional coupler.

16. The trans-radix quantum circuit of claim 15 , wherein applying the quantum circuit element to the first radix-2 qubit and the second radix-2 qubit, comprises providing the first radix-2 qubit to a first face or second face of the optical four-port directional coupler and the second radix-2 qubit to a third face or a fourth face of the optical four-port directional coupler.

17. A method, comprising

operating an optical four-port directional coupler as a trans-radix two-qubit QIP circuit element by:

providing a first radix-2 qubit at a first port or a second port of the optical four-port directional coupler; and

providing a second radix-2 qubit at a third port or a fourth port of the optical four-port directional coupler.

18. The method of claim 17 , wherein the first radix-2 qubit and the second radix-2 qubit are time aligned at the first port, second port, third port or fourth port.

19. A trans-radix quantum circuit, comprising:

a quantum circuit element implementing a radix-2 quantum operation, the quantum circuit element comprising one or more radix-r circuit elements where r>2.

20. The trans-radix quantum circuit of claim 19 , further comprising one more radix-2 circuit elements, wherein an input port or output port of the one or more radix-r quantum circuit elements support an input or output of a radix-2 qubit transmission channel.