Trapping Alkaline Earth Rydberg Atoms Optical Tweezer Arrays

Abstract

Neutral atom qubits with Rydberg-mediated interactions are a leading platform for developing large-scale coherent quantum systems. In the majority of experiments to date, the Rydberg states are not trapped by the same potential that confines ground state atoms, resulting in atom loss and constraints on the achievable interaction time. In this work, we demonstrate that the Rydberg states of an alkaline earth atom, ytterbium, can be stably trapped by the same red-detuned optical tweezer that also confines the ground state, by leveraging the polarizability of the Yb + ion core. Using the previously unobserved 3 S1 series, we demonstrate trapped Rydberg atom lifetimes exceeding 100 µs, and observe no evidence of auto-or photo-ionization from the trap light for these states. We measure a coherence time of T2 = 59 µs between two Rydberg levels, exceeding the 28 µs lifetime of untrapped Rydberg atoms under the same conditions. These results are promising for extending the interaction time of Rydberg atom arrays for quantum simulation and computing, and are vital to capitalize on the extended Rydberg lifetimes in circular states or cryogenic environments.

Analyzing the Rydberg-based omg architecture for $^{171}$Yb nuclear spins

“…In particular, the 3 S 1 series has been mapped out in Ref. [10]. The energy levels for the 171 Yb F = 3/2 3 S 1 series are obtained by finding the effective quantum numbers from the measured levels and applying them in (A4).…”

“…[68], while the triplet µ 1 is taken from Ref. [10]. Specifically, the electronic reaction matrix is diagonal in the singlet-triplet representation, i.e.…”

“…Inspired by recent work [12,14,16], we consider Rydberg-mediated entanglement via the 3 P 0 ↔ 3 S 1 transition, where the latter has a principal quantum number of n ≈ 60 [see Fig 1(a)]. However, we note that a twophoton transition from the 1 S 0 ground state could be used instead [10,15,19,47] at the expense of higher optical power and additional complexity, and was recently used to perform two-qubit gates on the nuclear spin qubit in the ground state of 171 Yb at low field (≈ 4 G) [19]. We consider two-qubit gate operations with qubits defined by any combination of {↓ a , ↑ a , ↓ c , ↑ c }.…”

“…The state energies in this series can thus be modeled using the known energies of the 3 S 1 series in the bosonic isotope 174 Yb (obtained from Ref. [10]) plus the hyperfine splitting ∆ HFS = 2π × 12.6 GHz of the 171 Yb ionic core (see Appendix B). Figure 1(d) shows both the F = 1/2 and F = 3/2 series near n * = 55, where the figure of merit is the energy separation between the two series and the associated resolvability of a given state.…”

“…Individually trapped neutral atoms with interactions mediated by highly-excited Rydberg states have become a prominent platform for quantum science [1][2][3]. Most research to date with arrays of neutral atoms has been conducted with alkali species, but alkaline earth(-like) atoms (AEAs) are gaining prominence after bosonic (I = 0) [4][5][6][7][8][9][10][11][12][13][14][15][16] and fermionic (I > 0) [17][18][19] isotopes recently joined this field. AEAs offer qualitative differences and quantitative advantages over alkalis.…”