Quantum simulation using photons and room temperature atoms

Lorenzo M. Procopio, Philip John Walther

Jiefei Wang, Ruosong Mao, Xingqi Xu +9 more

Quantum simulation offers an analog approach for exploring exotic quantum phenomena using controllable platforms, typically necessitating ultracold temperatures to maintain the quantum coherence. Superradiance lattices (SLs) have been harnessed to simulate coherent topological physics at room temperature, but the thermal motion of atoms remains a notable challenge in accurately measuring the physical quantities. To overcome this obstacle, we implement a velocity scanning tomography technique to discern the responses of atoms with different velocities, allowing cold-atom spectroscopic resolution within room-temperature SLs. By comparing absorption spectra with and without atoms moving at specific velocities, we can derive the Wannier-Stark ladders of the SL across various effective static electric fields, their strengths being proportional to the atomic velocities. We extract the Zak phase of the SL by monitoring the ladder frequency shift as a function of the atomic velocity, effectively demonstrating the topological winding of the energy bands. Our research signifies the feasibility of room-temperature quantum simulation and facilitates their applications in quantum information processing.

Zheng Li, Chenxi Shi, Yuan Yang +1 more

With the development of quantum physics, quantum simulation technology has become more mature and has many applications in real life. This paper introduces two methods of quantum simulation: ultracold atom simulation and integrated photonic simulation. First, ultracold simulation is easy to observe and highly manageable, and its experimental results often agree with the theory. Besides these, it also has limitations. Thus, how to surpass the general theoretical simulation is essential in the future. Then for integrated quantum photonics, it is easy to manufacture, available at room temperature and allows long simulations with a high degree of experimental control. With a few components optimized, large-scale quantum photonic circuits with many photons can likely become a reality in the coming decade.

Laurent Sanchez-Palencia

Matteo Sanna, Alessio Baldazzi, Nicolò Broseghini +7 more

Quantum simulators are controllable quantum sys-tems that can be used to reproduce the states and the dynamics of other quantum systems object of study. The ease to manipulate single photons on a chip at room temperature without deco-herence issues has made integrated photonics one of the most viable technologies for processing quantum information. Many demonstrations have been reported over the past fifteen years, included the simulation of complex and many-body interactions. Combining quantum light sources, reconfigurable circuits and high-efficiency single-photon detectors together on a single chip is an extremely challenging goal, still taking a lot of scientific and technological efforts worldwide. Here, we report emergent results along this direction. On a silicon nitride photonic platform, we separately show a source of photon pairs based on a microring, high-performance wavelength filters based on Mach-Zehnder in-terferometers and silicon single-photon avalanche diodes directly coupled to the photonic waveguides. The demonstration of these fundamental building blocks represents a starting point for the realization of a photonic quantum simulator operated entirely on a single chip working at room temperature.

Monika Schleier-Smith