Implementing two-qubit gates at the quantum speed limit

Abstract

The speed of elementary quantum gates, particularly two-qubit gates, ultimately sets the limit on the speed at which quantum circuits can operate. In this work, we experimentally demonstrate commonly used two-qubit gates at nearly the fastest possible speed allowed by the physical interaction strength between two superconducting transmon qubits. We achieve this quantum speed limit by implementing experimental gates designed using a machine learning inspired optimal control method. Importantly, our method only requires the single-qubit drive strength to be moderately larger than the interaction strength to achieve an arbitrary two-qubit gate close to its analytical speed limit with high fidelity. Thus, the method is applicable to a variety of platforms including those with comparable single-qubit and two-qubit gate speeds, or those with always-on interactions. We expect our method to offer significant speedups for non-native two-qubit gates that are typically achieved with a long sequence of single-qubit and native two-qubit gates.

11 pages, 9 figures, accepted version

References in corpus (6)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Experimental Comparison of Two Quantum Computing Architectures
• Complete universal quantum gate set approaching fault-tolerant thresholds with superconducting qubits
• High fidelity two-qubit gates on fluxoniums using a tunable coupler
• Analytical approach to swift nonleaky entangling gates in superconducting qubits
• Overlap junctions for high coherence superconducting qubits

Cited by in corpus (10)

• Quantum Computing: Vision and Challenges
• Single-Atom Verification of the Optimal Trade-Off between Speed and Cost in Shortcuts to Adiabaticity
• STIRAP-Inspired Robust Gates for a Superconducting Dual-Rail Qubit
• Observation of discrete charge states of a coherent two-level system in a superconducting qubit
• Direct pulse-level compilation of arbitrary quantum logic gates on superconducting qutrits
• Cost of Emulating a Small Quantum Annealing Problem in the Circuit-Model
• GPU-accelerated Effective Hamiltonian Calculator
• Quantum Speed Limits from Symmetries in Quantum Control
• Quantum speed limits in dephasing dynamics of a qubit system coupled to thermal environments
• Hamiltonian simulation with explicit formulas for Digital-Analog Quantum Computing