Optical simulator of the quantum Fourier transform

Abstract

Experimental realizations of the quantum Fourier transform (QFT) are currently limited to qubits, which limits experimental tests of theoretical predictions of QFT performance under various noise conditions and their scaling in n. As a possible strategy to overcome this limitation, we show that an exact one-to-one correspondence exists between the QFT and a specially designed optical grating with a curved screen. This device allows the experimental simulation of the QFT, including defects, up to qubit numbers around n = 20, not currently accessible to direct quantum experimentation. The experimental realizability of the device is discussed.