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)
À lire aussi
On-chip generation of spatial entanglement
The QITE team just published in Phys. Rev. Lett. its work on the generation of spatial entanglement in nonlinear waveguide arrays, in collaboration with C2N and INPHYNI. Combining the generation and manipulation of complex quantum states of light on a single chip is a...
An hybrid III-V / Silicon source of photon pairs
The QITE team of MPQ lab, in collaboration with C2N lab, INPHYNI and STMicroelectronics, has just published its work on the development of integrated hybrid sources of entangled photons in PRX Quantum. Combining the generation and manipulation of quantum states of...
Emergent quantum phase transition in superconducting circuits
The THEORIE team has recently published a significant theoretical study in Nature Communications on the topic of quantum critical phenomena. This research addresses a current debate that questions the traditional understanding of dissipative quantum phase transitions...
Probing and manipulating the superconducting state of NbSe2 in the 2D limit
Context:. The dynamics of superconductors (SC) driven out-of-equilibrium is governed by their collective mode spectrum, and in particular the SC amplitude mode which is an analog of the Higgs mode in high-energy physics [1]. In many materials the coexistence of SC...