Published: 3 April 2016, 13:22
Together with colleagues from the University of Innsbruck, the University of Aarhus, the INAOE in Mexico and the CREOL of the University of Central Florida, ACP principal scientists Stefan Nolte and Alexander Szameit have just published an original research article titled "Implementation of quantum and classical discrete fractional Fourier transforms" in Nature Communications (Weimann et al., Nature Comm. 7, 11027, 2016). In their work, they report on the realization of Discrete Fractional Fast Fourier Transforms (DFrFTs) of one-dimensional optical signals based on an integrated lattice of evanescently coupled waveguides. In these photonic arrangements, the inter-channel couplings are designed in such a way that the system readily performs the DFrFT of any incoming signal. The signal evolution is governed by the Schrödinger equation and the associated Hamilton operator is known as the Jx-operator in the quantum theory of angular momentum or likewise as the Heisenberg XY model from the quantum theory of ferromagnetism. The authors foresee that the inherent versatility of this approach will make other realizations of the DFrFT, the FT and the fast Fourier transform recognizably simple and thus may open the door to many interesting applications in integrated quantum computation.