Reconfigurable cluster-state generation in specially poled nonlinear waveguide arrays

Abstract

We present a new approach for generating cluster states on-chip, with the state encoded in the spatial component of the photonic wavefunction. We show that for spatial encoding, a change of measurement basis can improve the practicality of cluster state algorithm implementation, and demonstrate this by simulating Grover's search algorithm. Our state generation scheme involves shaping the wavefunction produced by spontaneous parametric down-conversion in on-chip waveguides using specially tailored nonlinear poling patterns. Furthermore the form of the cluster state can be reconfigured quickly by driving different waveguides in the array. Importantly, this approach allows cluster states to be generated directly from a nonlinear optical process, without requiring additional optical transformations to be applied after the initial quantum state is generated.

Quantum-state creation in nonlinear-waveguide arrays

“…It can be driven in either the low or high gain regime, corresponding to the generation of probabilistic single pairs or squeezed states and also allows for lowloss photon operations and each mode is spatially separated for easy detection setups. State generation in this nonlinear WGA setup has been considered in the continuous variable regime of quantum optics [12][13][14][15][16][17]. There has also been experimental implementations of this setup [10,18,19] In this work we explore a nonlinear WGA, consisting of many coupled channels, in a regime where the PDC photon pairs are highly non-degenerate in frequency.…”

One-hundred step measurement-based quantum computation multiplexed in the time domain with 25 MHz clock frequency

“…These features make MBQC an appealing experimental candidate as state preparations and measurements tend to be simpler than direct implementations of quantum gates. Generation of cluster states [9][10][11][12][20][21][22][23][24][25] and the demonstration of small-scale MBQC 21,23,[25][26][27][28] in various systems have both already been achieved. To move from smallscale MBQC to large-scale MBQC, large-scale cluster states are required.…”