Session G69: Tweezer Arrays

Dual-species Rydberg array of rubidium and cesium atoms

Quantum information processing architectures that leverage multiple modalities of qubits offer compelling strategies for suppressing qubit errors, performing quantum non-demolition measurements, and executing auxiliary-qubit based quantum protocols. In this talk I will present the latest results from our dual-species atom array composed of individually controlled rubidium and cesium atomic qubits. Using species-selective trapping, we demonstrate independent placement of single rubidium and cesium atoms in arbitrary geometries up to 512 trapping sites and observe negligible crosstalk [1]. This negligible crosstalk enables reloading of one set of atomic qubits into the array while maintaining quantum coherence in the other, paving the way towards continuous-mode operation of atom array processors. Furthermore, I will discuss how we use mid-circuit measurements on one atomic species to perform corrections or apply quantum gates on the other species all within the execution of a quantum circuit [2]. Combining these feedforward operations with programmable intraspecies and interspecies Rydberg gates will enable auxiliary-qubit-assisted protocols, as required for quantum error correction and measurement-based state preparation.

 

[1] K. Singh et al. Phys. Rev. X 12, 011040 (2022)

[2] K. Singh, C.E. Bradley, S. Anand et al., arXiv:2208.11716 (2022)   

Quantum processors based on atom arrays

We will discuss the recent advances involving programmable, coherent manipulation of quantum systems based on neutral atom arrays excited into Rydberg states, allowing the control over several hundred qubits in two dimensions. Recent developments involving both analog and digital quantum simulations and quantum information processing will be described. In particular, the realization of novel quantum processing architecture based on dynamically reconfigurable entanglement and the steps towards quantum error correction will be discussed. Finally, we will discuss our efforts towards using these techniques for realization of large-scale quantum processors with protected qubits.   

Towards mid-circuit measurements with nuclear spin qubits in an optical tweezer array

Neutral atoms in tweezers have emerged as a versatile quantum science architecture with exciting capabilities, such as programmability and single-site readout. A growing effort seeks to expand these, exploiting unique properties offered by more complex atoms and molecules. Here, we will present a platform based on one such atom: ytterbium 171 and describe our recent work on adding mid-circuit measurements, a key ingredient in quantum error correction, to the toolbox. 

Ytterbium-171 has isolated nuclear spin-½–a native qubit with second-scale coherence times; while its narrow-line electronic transitions open a playground for MHz-scale manipulations on the single qubits, low-entropy state-preparation and fast readout. Employing  microsecond-scale control of the clock transition and site-selectivity enabled by tweezer light shifts, we can shelve a subset of qubits to the clock state and measure the reminder; we will report our progress using this technique to realize mid-circuit measurements along with lossless state-sensitive detection.    

Neutral atom quantum computing with Ytterbium-171

Quantum computing with neutral atoms has progressed rapidly in recent years, combining large system sizes, flexible and dynamic connectivity, and quickly improving gate fidelities. The pioneering work in this field has been implemented using alkali atoms, primarily rubidium and cesium. However, divalent, alkaline-earth-like atoms such as ytterbium offer significant technical advantages. In this talk, I will present our progress on quantum computing using 171-Yb atoms, including high-fidelity imaging, nuclear spin qubits with extremely long coherence times, and two-qubit gates on nuclear spins using Rydberg states [1,2]. I will also discuss several unexpected benefits of alkaline-earth-atoms: an extremely robust and power-efficient local gate addressing scheme [3], and a novel approach to quantum error correction called “erasure conversion”, which has the potential to implement the surface code with a threshold exceeding 4%, using the unique level structure of 171-Yb to convert spontaneous emission events into erasure errors [4].

 

[1] S. Saskin et al, Phys. Rev. Lett. 122, 143002 (2019).

[2] A. P. Burgers et al, PRX Quantum 3, 020326 (2022).

[3] S. Ma, A. P. Burgers, et al, Phys. Rev. X 12, 021028 (2022).

[4] Y. Wu, et al, Nat. Comms. 13, 4657 (2022).