High-fidelity controlled-phase gates for distinguishable quantum walkers via extended interactions

• URL: http://arxiv.org/abs/2608.09301v1
• Date: Mon, 10 Aug 2026 08:50:10 GMT
• Title: High-fidelity controlled-phase gates for distinguishable quantum walkers via extended interactions
• Abstract summary: We investigate the implementation of controlled-phase gates with quantum walks in a dual-rail encoding through the use of interacting particles.<n>We show that extending the interaction range beyond on-site or first-neighbor terms provides sufficient control over the scattering potential to engineer CP gates with distinguishable particles.<n>We find that while distinguishable-particle scattering alone exhibits slightly lower fidelity than the indistinguishable case, the overall architecture that we propose avoids the additional single-particle gates required for routing indistinguishable particles.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We investigate the implementation of controlled-phase (CP) gates with quantum walks in a dual-rail encoding through the use of interacting particles. While previous proposals have focused on indistinguishable particles (bosons or fermions) to achieve unitary fidelity for plane-wave scattering, practical implementations require finite-size wavepackets and routing through single-particle gates, both factors that introduce unavoidable fidelity losses. We show that extending the interaction range beyond on-site or first-neighbor terms provides sufficient control over the scattering potential to engineer CP gates with distinguishable particles that match the ideal bosonic/fermionic performance. For finite Gaussian wavepackets, we derive analytical approximations for the gate fidelity in terms of the transmission coefficient's magnitude and phase derivatives. We find that while distinguishable-particle scattering alone exhibits slightly lower fidelity than the indistinguishable case, the overall architecture that we propose avoids the additional single-particle gates required for routing indistinguishable particles. The roundabout gates needed for the latter indeed introduce fidelity losses approximately one order of magnitude larger than the interaction-induced losses, making the distinguishable-particle approach competitive for practical implementations. Our results establish multi-neighbor interactions as a tool for quantum information processing with continuous-time quantum walks and provide quantitative guidelines for optimizing gate fidelities in finite-size systems.

Related papers

• Quantum Decision Theory for Displacement Detection with Finite-Energy GKP States [46.2474896050764]
  We develop a framework for detecting phase-space displacements with finite-energy, $d$-level Gottesman-Kitaev-Preskill (GKP) probes.<n>For single-mode and entanglement-assisted architectures, we derive the Bayesian minimum-error probability.<n>We benchmark the resulting protocols against coherent-state, direction-matched squeezed-vacuum, and twin-beam schemes.
  arXiv  Detail & Related papers  (2026-08-08T10:32:05Z)
• 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)
• Charge-parity switching effects and optimisation of transmon-qubit design parameters [0.0]
  We identify optimal ranges for qubit design parameters, grounded in comprehensive noise modeling. A charge-parity switch can be the dominant quasiparticle-related error source of a two-qubit gate. We present a performance metric for quantum circuit execution.
  arXiv  Detail & Related papers  (2023-09-29T12:05:27Z)
• Harnessing high-dimensional temporal entanglement using limited interferometric setups [41.94295877935867]
  We develop the first complete analysis of high-dimensional entanglement in the polarization-time-domain. We show how to efficiently certify relevant density matrix elements and security parameters for Quantum Key Distribution. We propose a novel setup that can further enhance the noise resistance of free-space quantum communication.
  arXiv  Detail & Related papers  (2023-08-08T17:44:43Z)
• Heralded nonlocal quantum gates for distributed quantum computation in a decoherence-free subspace [4.513705164435675]
  We propose a heralded protocol for implementing nontrivial quantum gates on two stationary qubits coupled to spatially separated cavities. By dynamically controlling the evolution of the composite system, nonlocal two-qubit quantum gates can be achieved without real excitations of either cavity modes or atoms.
  arXiv  Detail & Related papers  (2023-05-01T03:19:07Z)
• Two-Particle Scattering on Non-Translation Invariant Line Lattices [0.0]
  Quantum walks have been used to develop quantum algorithms since their inception. We show that a CPHASE gate can be achieved with high fidelity when the interaction acts only on a small portion of the line graph.
  arXiv  Detail & Related papers  (2023-03-08T02:36:29Z)
• Suppressing Amplitude Damping in Trapped Ions: Discrete Weak Measurements for a Non-unitary Probabilistic Noise Filter [62.997667081978825]
  We introduce a low-overhead protocol to reverse this degradation. We present two trapped-ion schemes for the implementation of a non-unitary probabilistic filter against amplitude damping noise. This filter can be understood as a protocol for single-copy quasi-distillation.
  arXiv  Detail & Related papers  (2022-09-06T18:18:41Z)
• Coherent effects contribution to a fast gate fidelity in ion quantum computer [47.187609203210705]
  We develop a numerical model for full simulation of coherence effects using a linear ion microtrap array and a 2D microtrap array. We have also studied the dependency of the gate fidelity on the laser power fluctuations.
  arXiv  Detail & Related papers  (2021-12-12T12:53:00Z)
• Analytical and experimental study of center line miscalibrations in M\o lmer-S\o rensen gates [51.93099889384597]
  We study a systematic perturbative expansion in miscalibrated parameters of the Molmer-Sorensen entangling gate. We compute the gate evolution operator which allows us to obtain relevant key properties. We verify the predictions from our model by benchmarking them against measurements in a trapped-ion quantum processor.
  arXiv  Detail & Related papers  (2021-12-10T10:56:16Z)
• Robust Nonadiabatic Holonomic Quantum Gates on Decoherence-Protected Qubits [4.18804572788063]
  We propose a scheme for quantum manipulation by combining the geometric phase approach with the dynamical correction technique. Our scheme is implemented on the superconducting circuits, which also simplifies previous implementations.
  arXiv  Detail & Related papers  (2021-10-06T14:39:52Z)
• 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)
• Accurate methods for the analysis of strong-drive effects in parametric gates [94.70553167084388]
  We show how to efficiently extract gate parameters using exact numerics and a perturbative analytical approach. We identify optimal regimes of operation for different types of gates including $i$SWAP, controlled-Z, and CNOT.
  arXiv  Detail & Related papers  (2021-07-06T02:02:54Z)
• Quantum control landscape for ultrafast generation of single-qubit phase shift quantum gates [68.8204255655161]
  We consider the problem of ultrafast controlled generation of single-qubit phase shift quantum gates. Globally optimal control is a control which realizes the gate with maximal possible fidelity. Trap is a control which is optimal only locally but not globally.
  arXiv  Detail & Related papers  (2021-04-26T16:38:43Z)

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.