High-dimensional entangled states of light provide novel possibilities for quantum information, from fundamental tests of quantum mechanics to enhanced computation and communication protocols. In this context, the frequency degree of freedom combines the assets of robustness to propagation and easy handling with standard telecommunication components. Parallelly, the implementation of these concepts on functional and scalable devices is another major challenge of quantum technologies.
Wigner function (artistic view) of entangled photons exhibiting either a fermionic (red) or bosonic (blue) behavior, generated by a semiconductor chip.
The QITe team of Laboratory MPQ, in collaboration with the Centre for Nanoscience and Nanotechnologies, has addressed this double challenge by demonstrating two novel techniques for generating and manipulating frequency-entangled photon pairs using miniaturized semiconductor chips (AlGaAs).
The first method, published in npj Quantum Information, uses a nonlinear waveguide to generate two-photon frequency combs over a wide spectral range, and to control their symmetry by simply adjusting the frequency of the pump beam and introducing a time delay between the photons of each pair.
The second method, published in Optica, is based on a semiconductor microcavity illuminated by a transverse laser beam. By controlling the spatial profile of this pump beam, the correlations and the symmetry of the quantum state can be engineered, so that the produced photons behave either as bosons or fermions.
These results pave the way for the realization of complex protocols in an integrated manner and for the out-of-the-lab deployment of quantum technologies based on high-dimensional quantum states, which could be used in future quantum networks.
Link to the coverage article on the INP website
Contact:
M. Amanti, F. Baboux, S. Ducci
References:
Generation and symmetry control of quantum frequency combs, G. Maltese, M. Amanti, F. Appas, G. Sinnl, A. Lemaître, P. Milman, F. Baboux, S. Ducci, npj Quantum Information 6, 13 (2020)
Engineering two-photon wavefunction and exchange statistics in a semiconductor chip, S. Francesconi, F. Baboux, A. Raymond, N. Fabre, G. Boucher, A. Lemaître, P. Milman, M. Amanti, S. Ducci, Optica 7, 316 (2020)
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