Electrical Simulation of Quantum Algorithms

The importance of quantum algorithms is increasingly understood, but there are presently few simple, cheap experiments to illustrate their operation. It was shown that simulations of quantum algorithms can be performed in optical experiments.^1 Specifically, beam splitters and phase shifters mimic Hadamard and phase shift gates in the quantum network. Such essentially classical simulators scale poorly but provide insight nonetheless. Electrical circuits can simulate these optical elements, representing quantum states with AC currents rather than light waves. Arrangements of these can emulate few-qubit algorithms. In particular, we simulate a Mach-Zehnder interferometer and Grover's algorithm on 2 qubits^2. The latter will be demonstrated. [1] N.J. Cerf phet al. Phys. Rev. A, 57, R1477 (1998). [2] P.G. Kwiat phet al. J. Mod. Optics, 47, 257 (2000).