Three-qubit entangling gates with simultaneous exchange controls in spin qubit systems

• URL: http://arxiv.org/abs/2512.13558v1
• Date: Mon, 15 Dec 2025 17:16:48 GMT
• Title: Three-qubit entangling gates with simultaneous exchange controls in spin qubit systems
• Authors: Miguel G. Rodriguez, Yun-Pil Shim,
• Abstract summary: Pairwise exchange couplings have long been the standard mechanism for entangling spin qubits in semiconductor systems.<n>We present an alternative approach: multi-qubit entangling gate operations that simultaneously drive the exchange couplings between multiple pairs of spin qubits.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Pairwise exchange couplings have long been the standard mechanism for entangling spin qubits in semiconductor systems. However, implementing quantum circuits based on pairwise exchange gates often requires a lengthy sequence of elementary gate operations. In this work, we present an alternative approach: multi-qubit entangling gate operations that simultaneously drive the exchange couplings between multiple pairs of spin qubits. We explore three spin qubit systems in linear or triangular configurations. We derive analytical expressions for these multi-exchange entangling operations and demonstrate how to use the resulting three-qubit gates to construct quantum circuits capable of generating standard entangled states such as GHZ and W states, and the Toffoli gate, by optimizing control parameters. Our results show that this multi-qubit strategy significantly reduces the number of required operations, offering a pathway to more efficient, shallower, and more coherent circuits for spin-qubit processors.

Related papers

• Parallel Quantum Gates via Scalable Subsystem-Optimized Robust Control [9.72599396930123]
  Crosstalk between qubits impedes the achievement of high gate fidelities and renders full Hilbert-space control optimization prohibitively difficult.<n>Here, we overcome this challenge by reducing the full-system optimization to crosstalk-robust control over constant-sized subsystems.<n>Within this framework, we construct analytical pulse solutions for parallel single-qubit gates and numerical pulses for parallel multi-qubit operations.
  arXiv  Detail & Related papers  (2026-01-05T10:50:40Z)
• Accelerating Transpilation in Quantum Machine Learning with Haiqu's Rivet-transpiler [45.88028371034407]
  We develop the Rivet transpiler, which accelerates transpilation by reusing previously transpiled circuits.<n>We demonstrate up to 600% improvement in transpilation time for quantum layerwise learning.
  arXiv  Detail & Related papers  (2025-08-29T06:00:29Z)
• Parity Cross-Resonance: A Multiqubit Gate [5.6995215414894735]
  We present a native three-qubit entangling gate that exploits engineered interactions to realize control-control-target and control-target-target operations.<n>We show it can be utilized in several ways, for example, in GHZ triplet state preparation.
  arXiv  Detail & Related papers  (2025-08-14T16:26:32Z)
• Performance Characterization of a Multi-Module Quantum Processor with Static Inter-Chip Couplers [63.42120407991982]
  Three-dimensional integration technologies such as flip-chip bonding are a key prerequisite to realize large-scale superconducting quantum processors.<n>We present a design for a multi-chip module comprising one carrier chip and four qubit modules.<n>Measuring two of the qubits, we analyze the readout performance, finding a mean three-level state-assignment error of $9 times 10-3$ in 200 ns.<n>We demonstrate a controlled-Z two-qubit gate in 100 ns with an error of $7 times 10-3$ extracted from interleaved randomized benchmarking.
  arXiv  Detail & Related papers  (2025-03-16T18:32:44Z)
• Fast quantum gates for exchange-only qubits using simultaneous exchange pulses [0.0]
  This paper develops a faster implementation of single-qubit gates using simultaneous exchange pulses.<n>We show that subsequences on three spins in two-qubit gates could be implemented in fewer steps.<n>We experimentally demonstrate and characterize a simultaneous exchange implementation of $X$ rotations in a SiGe quantum dot device.
  arXiv  Detail & Related papers  (2024-09-09T17:45:17Z)
• A diverse set of two-qubit gates for spin qubits in semiconductor quantum dots [5.228819198411081]
  We propose and verify a fast composite two-qubit gate scheme to extend the available two-qubit gate types. Our gate scheme limits the parameter requirements of all essential two-qubit gates to a common JDeltaE_Z region. With this versatile composite gate scheme, broad-spectrum two-qubit operations allow us to efficiently utilize the hardware and the underlying physics resources.
  arXiv  Detail & Related papers  (2024-04-29T13:37:43Z)
• Multi-qubit DC gates over an inhomogeneous array of quantum dots [0.0]
  We study a family of multi-qubit gates implementable over an array of quantum dots by DC evolution.<n>A useful representation of the computational Hamiltonian is proposed for a dot-array with strong spin-orbit coupling effects.<n>Examples of such multi-qubit gates and their applications in quantum error correction and quantum algorithms are also explored.
  arXiv  Detail & Related papers  (2024-03-11T16:49:56Z)
• Direct pulse-level compilation of arbitrary quantum logic gates on superconducting qutrits [36.30869856057226]
  We demonstrate any arbitrary qubit and qutrit gate can be realized with high-fidelity, which can significantly reduce the length of a gate sequence. We show that optimal control gates are robust to drift for at least three hours and that the same calibration parameters can be used for all implemented gates.
  arXiv  Detail & Related papers  (2023-03-07T22:15:43Z)
• Demonstration of tunable three-body interactions between superconducting qubits [38.98439939494304]
  We present a superconducting circuit architecture in which a coupling module mediates 2-local and 3-local interactions. The 3-local interaction is coherently tunable over several MHz via the coupler flux biases and can be turned off.
  arXiv  Detail & Related papers  (2022-05-09T20:23:43Z)
• Realization of arbitrary doubly-controlled quantum phase gates [62.997667081978825]
  We introduce a high-fidelity gate set inspired by a proposal for near-term quantum advantage in optimization problems. By orchestrating coherent, multi-level control over three transmon qutrits, we synthesize a family of deterministic, continuous-angle quantum phase gates acting in the natural three-qubit computational basis.
  arXiv  Detail & Related papers  (2021-08-03T17:49:09Z)
• Realization of high-fidelity CZ and ZZ-free iSWAP gates with a tunable coupler [40.456646238780195]
  Two-qubit gates at scale are a key requirement to realize the full promise of quantum computation and simulation. We present a systematic approach that goes beyond the dispersive approximation to exploit the engineered level structure of the coupler and optimize its control. We experimentally demonstrate CZ and $ZZ$-free iSWAP gates with two-qubit interaction fidelities of $99.76 pm 0.07$% and $99.87 pm 0.23$%, respectively.
  arXiv  Detail & Related papers  (2020-11-02T19:09:43Z)
• Improving the Performance of Deep Quantum Optimization Algorithms with Continuous Gate Sets [47.00474212574662]
  Variational quantum algorithms are believed to be promising for solving computationally hard problems. In this paper, we experimentally investigate the circuit-depth-dependent performance of QAOA applied to exact-cover problem instances. Our results demonstrate that the use of continuous gate sets may be a key component in extending the impact of near-term quantum computers.
  arXiv  Detail & Related papers  (2020-05-11T17:20:51Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.