Speakers
Description
Quantum computation harnesses the collective properties of quantum states, such as superposition, interference, and entanglement, to perform calculations, can greatly enhance the computing power. Physically, there are many candidates of quantum systems to implement quantum computation and simulation. In this lecture, I will introduce quantum computation and simulation with photons and cold atoms.
By developing high-performance quantum light sources, the multi-photon interference has been scaled up to implement boson sampling with up to 76 photons out of a 100-mode interferometer, which yields a Hilbert state space dimension of 1030 and a rate that is 1014 faster than using the state-of-the-art simulation strategy on supercomputers. Such a demonstration of quantum computational advantage is a much-anticipated milestone for quantum computing. The special-purpose photonic platform will be further used to investigate practical applications linked to the Gaussian boson sampling, such as graph optimization and quantum machine learning.
Ultracold atoms constitute a unique physical system for studying strongly correlated quantum many-body physics, and promise a great potential for quantum simulation. A new method of staggered-immersion cooling has been demonstrated in experiment leading to dramatic reduction of defects (from 10% to 0.8%) in a 2D lattice of 10k sites. Based on this, 1250 pairs of entangled atoms are prepared with a fidelity of 99.3%. This well-controlled quantum system consisting 71 lattice sites is used to model the Hamiltonian of a 1D lattice gauge theory with gauge symmetry of U(1), the Schwinger model. Furthermore, the properties of LGTs, such as quantum thermalization, have been studied. It is expected that, quantum simulation tasks outperforming relevant numerical calculations with classical supercomputers are likely to be demonstrated with the state-of-the-art cold-atom quantum simulators.
