Optical simulator of the quantum Fourier transform

Experimental realizations of the quantum Fourier transform (QFT) are currently limited to n <= 3 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. Copyright (C) EPLA, 2016