Ytterbium nuclear-spin qubits in an optical tweezer array

Abstract

We report on the realization of a fast, scalable, and high-fidelity qubit architecture, based on 171 Yb atoms in an optical tweezer array. We demonstrate several attractive properties of this atom for its use as a building block of a quantum information processing platform. Its nuclear spin of 1/2 serves as a long-lived, coherent, two-level system, while its rich, alkaline-earth-like electronic structure allows for low entropy preparation, fast qubit control, and high fidelity readout. Using narrowline transitions, we present a near-deterministic loading protocol, which allows us to fill a 10×10 tweezer array with 92.73(8)% efficiency and a single tweezer with 96.0(1.4)% efficiency. Employing a robust optical approach, we perform sub-microsecond qubit rotations and characterize their fidelity through randomized benchmarking, yielding 5.2(5)×10 −3 error per Clifford gate. For quantum memory applications, we measure the coherence of our qubits with T * 2 =3.7(4) s and T2=8.1(7) s. Finally, we use 3D Raman sideband cooling to bring the atoms near their motional ground state, which will be central to future implementations of two-qubit gates that benefit from low motional entropy.

Subrecoil Clock-Transition Laser Cooling Enabling Shallow Optical Lattice Clocks

“…Strong intersite tunneling is observed in the form of Bloch oscillations at 6 E r , inducing a minimal frequency shift. The pulsed clocktransition cooling demonstrated here can benefit neutral atom quantum computing architectures [24,32,33], where lower temperatures suppress thermal dephasing to improve entanglement fidelity and qubit control [28,34] or to enhance single-atom detection fidelity [35]. It also benefits strategies for direct cooling towards quantum degeneracy [36][37][38], as well as simulations of quantum magnetism, Kondo lattice physics [39], and other Hamiltonians [24,32].…”

“…Evaporative cooling has been used to attain sub-µK temperature and quantum degeneracy [23,24], but is precluded in many applications because of atom loss and very long evaporation time. Techniques for additional cooling of strongly-confined atoms have recently been demonstrated, but these are generally limited to the resolvedsideband regime [21,[25][26][27][28]. Many trapped systems operate outside this regime, including most optical lattice clocks that employ a 1D lattice for metrological benefits.…”

Tweezer-programmable 2D quantum walks in a Hubbard-regime lattice

“…This is accomplished by introducing a platform that combines the programmability of optical tweezer arrays with a Hubbard-regime optical lattice that provides a clean environment for tunneling, and several thousand sites which are compatible with high-fidelity cooling, imaging, and coherent control [53] (see supplement). Beyond studies with itinerance, these capabilities can also be used to prepare large, well-controlled ensembles of atomic qubits for quantum information, simulation, and metrology [41,[53][54][55][56][57][58][59][60].…”

Sub-recoil clock-transition laser cooling enabling shallow optical lattice clocks

“…Strong intersite tunneling is observed in the form of Bloch oscillations at 6 E r , inducing a minimal frequency shift. The pulsed clocktransition cooling demonstrated here can benefit neutral atom quantum computing architectures [24,32,33], where lower temperatures suppress thermal dephasing to improve entanglement fidelity and qubit control [28,34] or to enhance single-atom detection fidelity [35]. It also benefits strategies for direct cooling towards quantum degeneracy [36][37][38], as well as simulations of quantum magnetism, Kondo lattice physics [39], and other Hamiltonians [24,32].…”