Quantum fluid of light on a microchip

A microchip that can be integrated with conventional electronics and is capable of forming a Bose-Einstein condensate when optically excited has been designed and realized for the first time.

Matter exists in different states: solid, liquid, gas and plasma. However, there is a fifth state: the Bose-Einstein condensate, which is able to link the behavior of particle systems at the microscopic level (governed by the laws of quantum mechanics) and the macroscopic level generally governed by classical physics.

In a recent study published in Nature, resulting from an international collaboration including INL researchers, a microchip capable of forming a Bose-Einstein condensate has been designed and realized for the first time. It is a condensate of light-matter hybrid quasiparticles called polaritons, forming a quantum fluid of light. This quantum state is obtained from a simple planar semiconductor waveguide, allowing the formation of quantum light fluids on a chip that can be integrated with conventional electronics. Remarkably, this condensation, instead of taking place at the minimum of an energy band (Figure a), took place in an intrinsically unstable state, the so-called saddle point (Figure b). This apparently paradoxical phenomenon is in fact possible thanks to the symmetry properties of the nanostructuring implemented on the waveguide, which protects the condensate particles from external perturbations. This discovery promises multiple applications: new types of lasers, optical circuits without dissipation for ultrafast computation and their application to neuromorphic computation thanks to strong interactions between the polarization condensates.


Contact: Hai Son NGUYEN


References:“Polariton Bose-Einstein condensate from a Bound State in the Continuum”
Ardizzone, F. Riminucci, S. Zanotti, A. Gianfrate, D. G. Suarez-Forero, F. Todisco, M. De Giorgi, D.Trypogeorgos, G. Gigli, K. Baldwin, L. Pfeiffer, D. Ballarini, H.S. Nguyen, D. Gerace, D. Sanvitto
Nature 605, 447–452 (2022)


Collaborations: Institute of Nanotechnology of the National Research Council of Lecce (CNR-Nanotec), Department of Physics of the University of Pavia, Princeton University, Lawrence Berkeley National Laboratory.

Formation d'un condensat de Bose-Einstein de polaritons a) dans un état traditionel : les particules occupent macroscopiquement un minimum d'énergie; b) dans un état intrinsèquement instable, la condensation est rendue possible par les propriétés de symétrie de la puce semi-conductrice convenablement nanostructurée, qui protègent l'état de condensation des perturbation extérieure.
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