A hardware-efficient Mølmer–Sørensen gate for superconducting quantum computers

Abstract

Abstract The Mølmer–Sørensen gate, a cornerstone entangling operation in trapped-ion systems, represents a promising alternative to standard entangling gates in superconducting quantum architectures. However, its performance on superconducting hardware has remained unverified. In this work, we present a hardware-efficient implementation of the Mølmer–Sørensen gate and characterize its performance using quantum process tomography (QPT) on IBM Quantum’s superconducting processors. Our implementation achieves a process fidelity of 92.47% on the real quantum hardware, a performance competitive with the 93.02% fidelity of the device’s native controlled-NOT (CX) gate. Furthermore, for the $$\vert {00} \rangle $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>|</mml:mo> <mml:mn>00</mml:mn> <mml:mo>⟩</mml:mo> </mml:mrow> </mml:math> input state, the gate prepares the target Bell state with $$94.2\%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>94.2</mml:mn> <mml:mo>%</mml:mo> </mml:mrow> </mml:math> success probability, confirming its correct logical operation. These results demonstrate that non-native entangling gates can be optimized to perform on par with hardware-native operations. This work expands the effective gate set for algorithm design on fixed-architecture processors and provides a critical benchmark for cross-platform gate evaluation, underscoring the role of hardware-aware compilation in advancing noisy intermediate-scale quantum (NISQ) computing.