Robust and Parallel Control of Many Qubits

Abstract

The rapid growth in size of quantum devices demands efficient ways to control them, which is challenging for systems with thousands of qubits or more. Here, we present a simple yet powerful solution: robust, site-dependent control of an arbitrary number of qubits in parallel with only minimal local tunability of the driving field. Inspired by recent experimental advances, we consider access to only one of three constrained local control capabilities: local control of either the phase or amplitude of the beam at each qubit, or individual $Z$ rotations. In each case, we devise parallelizable composite pulse sequences to realize arbitrary single-qubit unitaries robust against quasistatic amplitude and frequency fluctuations. Numerical demonstration shows that our approach outperforms existing sequences such as BB1 and CORPSE in almost all regimes considered, achieving average fidelity~$>0.999$ under a decoherence rate of~$\sim 10^{-5}$, even with a few percent amplitude and frequency error. Our results indicate that even for very large qubit ensembles, accurate, individual manipulation can be achieved despite substantial control inhomogeneity.

7+15 pages, 2+2 figures, 1+8 tables

References in corpus (12)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Demonstration of multi-qubit entanglement and algorithms on a programmable neutral atom quantum computer
• Tackling Systematic Errors in Quantum Logic Gates with Composite Rotations
• Arbitrarily accurate composite pulses
• Local optical control of the resonant dipole-dipole interaction between Rydberg atoms
• Single-Atom Addressing in Microtraps for Quantum-State Engineering using Rydberg Atoms
• Continuous operation of large-scale atom arrays in optical lattices
• Concatenated composite pulses compensating simultaneous systematic errors
• Architectural mechanisms of a universal fault-tolerant quantum computer
• High-fidelity error-resilient composite phase gates
• A scaled local gate controller for optically addressed qubits
• Construction of Arbitrary Robust One-Qubit Operations Using Planar Geometry