arXiv subjects

M. A. Perlin

Publications and source records attributed to M. A. Perlin.

4 recordsLinked to original sources

arXiv2025

A universal neutral-atom quantum computer with individual optical addressing and non-destructive readout

Quantum computers must achieve large-scale, fault-tolerant operation to deliver on their promise of transformational processing power [1-4]. This will require thousands or millions of high-fidelity quantum gates and similar numbers of qubits [5]. Demonstrations using neutral-atom qubits trapped and manipulated by lasers have shown that this modality can provide high two-qubit gate (CZ) fidelities and scalable operation [6-13]. However, the gates in these demonstrations are driven by lasers that do not resolve individual qubits, with universal computation enabled by physical mid-circuit shuttling of the qubits. This relatively slow operation may greatly extend runtimes for useful, large-scale computation. Here we demonstrate a universal neutral-atom quantum computer with gate rates limited by optical switching times, rather than shuttling, by individually addressing tightly focused laser beams at an array of single atoms. We achieve CZ fidelity of 99.35(4)% and local single-qubit RZ gate fidelity of 99.902(8)%. Moreover, we demonstrate non-destructive readout of alkali-atom qubits with 0.9(3)% loss, which boosts operational speed. This technique also enables us to measure a state-of-the-art CZ fidelity of 99.73(3)% when excluding atom-loss events, which may be mitigated through erasure conversion. Our results represent a critical step towards large-scale, fault-tolerant neutral-atom quantum computers that can execute computations on practical timescales.

quant-ph↗

arXiv2024

Architecture for fast implementation of qLDPC codes with optimized Rydberg gates

We propose an implementation of bivariate bicycle codes (Nature {\bf 627}, 778 (2024)) based on long-range Rydberg gates between stationary neutral atom qubits. An optimized layout of data and ancilla qubits reduces the maximum Euclidean communication distance needed for non-local parity check operators. An optimized Rydberg gate pulse design enables $\sf CZ$ entangling operations with fidelity ${\mathcal F}>0.999$ at a distance greater than $12~μ\rm m$. The combination of optimized layout and gate design leads to a quantum error correction cycle time of $\sim 1.28~\rm ms$ for a $[[144,12,12]]$ code, nearly a factor of two improvement over previous designs.

quant-ph↗

arXiv2022

SupercheQ: Quantum Advantage for Distributed Databases

We introduce Supercheq, a family of quantum protocols that achieves asymptotic advantage over classical protocols for checking the equivalence of files, a task also known as fingerprinting. The first variant, Supercheq-EE (Efficient Encoding), uses $n$ qubits to verify files with $2^{O(n)}$ bits -- an exponential advantage in communication complexity (i.e.~bandwidth, often the limiting factor in networked applications) over the best possible classical protocol in the simultaneous message passing setting. Moreover, Supercheq-EE can be gracefully scaled down for implementation on circuits with $\mathrm{poly}(n^\ell)$ depth to enable verification for files with $O(n^\ell)$ bits for arbitrary constant $\ell$. The quantum advantage is achieved by random circuit sampling, thereby potentially endowing circuits from recent quantum supremacy and quantum volume experiments with a practical application. We validate Supercheq-EE's performance at scale through GPU simulation motivated by Infleqtion's Sqale neutral atom QPU gateset. The second variant, Supercheq-IE (Incremental Encoding), also achieves arbitrary-polynomial advantage in fingerprint size ($n$ qubits to verify files with size $O(n^{\ell})$ bits), while supporting incremental updates to the fingerprint using only a constant number of $(\ell-1)$-qubit gates. Moreover, Supercheq-IE at $\ell=2$ ($\geq 3$) only requires Clifford gates (gates in the $\ell-1$ level of the Clifford hierarchy), ensuring relatively modest overheads for error-corrected implementation. We experimentally demonstrate proof-of-concepts on quantum hardware from Diraq (spin qubit) and IBM (superconducting). We envision Supercheq could be deployed in distributed data settings, accompanying replicas of important databases.

quant-ph↗

arXiv2018

Emergence of multi-body interactions in few-atom sites of a fermionic lattice clock

Alkaline-earth (AE) atoms have metastable clock states with minute-long optical lifetimes, high-spin nuclei, and SU($N$)-symmetric interactions that uniquely position them for advancing atomic clocks, quantum information processing, and quantum simulation. The interplay of precision measurement and quantum many-body physics is beginning to foster an exciting scientific frontier with many opportunities. Few particle systems provide a window to view the emergence of complex many-body phenomena arising from pairwise interactions. Here, we create arrays of isolated few-body systems in a fermionic ${}^{87}$Sr three-dimensional (3D) optical lattice clock and use high resolution clock spectroscopy to directly observe the onset of both elastic and inelastic multi-body interactions. These interactions cannot be broken down into sums over the underlying pairwise interactions. We measure particle-number-dependent frequency shifts of the clock transition for atom numbers $n$ ranging from 1 to 5, and observe nonlinear interaction shifts, which are characteristic of SU($N$)-symmetric elastic multi-body effects. To study inelastic multi-body effects, we use these frequency shifts to isolate $n$-occupied sites and measure the corresponding lifetimes. This allows us to access the short-range few-body physics free from systematic effects encountered in a bulk gas. These measurements, combined with theory, elucidate an emergence of multi-body effects in few-body systems of sites populated with ground-state atoms and those with single electronic excitations. By connecting these few-body systems through tunneling, the favorable energy and timescales of the interactions will allow our system to be utilized for studies of high-spin quantum magnetism and the Kondo effect.

cond-mat.quant-gas↗