Multimode quantum state engineering with femtosecond pulses

Daniele Fausti

Francesca Sansavini, Matthieu Ansquer, Tiphaine Kouadou +2 more

We generate multimode quantum states via single-pass femtosecond parametric down conversion in non-linear waveguides. We measure up to 14 squeezed spectral modes and pulse-by pulse squeezing. This enables the implementation of large quantum networks.

Tobias Brixner, Niels H. Damrauer, G. Gerber

Chihua Zhou Chihua Zhou, Changchun Zhang Changchun Zhang, haijiang liu +3 more

Nonclassical optical frequency combs play essential roles in quantum computation in the continuous variable regime. In this work, we generate multimode nonclassical frequency comb states using a degenerate type-I synchronously pumped optical parametric oscillator and directly observe the squeezing of the leading five temporal modes of femtosecond pulsed light. The overlapping spectra of these modes mean that the temporal modes are suitable for use in real-world quantum information applications.

Klaus M. Gheri, Päivi Törmä, P. Zoller

Aruto Hosaka, Masaya Tomita, Akihito OHMI +8 more

We propose a large-scale quantum simulator by multiplexing optical quantum modes in the frequency domain and arbitrarily mixing them as a boson sampling optical circuit to obtain Franc Condon Factor of large molecules. By shaping 785-nm femtosecond pump laser pulses, we generate multimode squeezed states via spontaneous parametric down conversion with a type-II PPKTP. Sum frequency mixing using a type-II PPLN between the multimode squeezed states and gate pulses that are shaped to the arbitrary superposition of the multi-spectral mode functions acts as programmable quantum gating. We complete the quantum simulation by time-dependent photon number detection at the sum-frequency wavelength at 517 nm. We describe the advantage of quantum mode manipulation in the frequency domain and place a special emphasis on group velocity dispersion engineering required to achieve them.