DOUBLE FEATURE M.Sc. Simon Karch and M.Sc. Renhao Tao

M.Sc. Simon Karch talks about: "Probing quantum many-body dynamics using subsystem Loschmidt echos"

The Loschmidt echo - the probability of a quantum many-body system to return to its initial state following a dynamical evolution - generally contains key information about a quantum system. However, it is typically exponentially small in system size, posing an outstanding challenge for experiments. In this talk, I will present our recent results using a quantum gas microscope to measure the subsystem Loschmidt echo — a quasi-local observable that captures key features of the Loschmidt echo.

M.Sc. Renhao Tao talks about: "A universal gate set for metastable qubits in 88 strontium"

Microscopically controlled neutral-atom arrays have emerged as a versatile platform for quantum simulation and quantum computing. Recent developments of neutral-atom quantum computers have been accelerated by demonstrations of high-fidelity single- and two-qubit gates.
In this talk, I will present our latest results on implementing a universal quantum gate set in strontium-88. First, I will show the benchmarking of single-qubit gates carried out between our qubit states (3P0 and 3P2), and species-specific features that enable efficient error mitigation on state-preparation and off-resonant scattering. Then, I will present high-fidelity control-Z gate, realized by a time-optimal, phase-modulated UV pulse coupling 3P0 to the highly excited, Rydberg state. Finally, I will demonstrate a novel qubit-state-resolved imaging technique which allows us to discriminate the signal of the qubit states from atom loss with high fidelity. Such a capability has major implication to low-error, Rydberg-based gates which are fundamentally limited by decay from Rydberg states.
Applications immediately on the horizon include analogue-digital simulators which greatly extend the toolbox of low-error analogue simulation with exquisite state preparation and characterization, and on-demand preparation of maximally entangled, metrologically relevant states.