This work introduces UDC-3, a three-pulse composite control sequence designed to suppress coherent drift in quantum gates. We experimentally evaluate UDC-3 inside a quantum teleportation protocol on the IBM Quantum Platform under a deliberately injected 5% over-rotation drift. Statevector simulations and hardware runs show that UDC-3 improves the teleportation fidelity from approximately 0.80 to 0.83, corresponding to a ~12% reduction in coherent error. This paper presents the methodology, circuit design, and experimental data.
This work introduces UDC-3, a three-pulse composite control sequence designed to suppress coherent drift in quantum gates. We experimentally evaluate UDC-3 inside a quantum teleportation protocol on the IBM Quantum Platform under a deliberately injected 5% over-rotation drift. Statevector simulations and hardware runs show that UDC-3 improves the teleportation fidelity from approximately 0.80 to 0.83, corresponding to a ~12% reduction in coherent error. This paper presents the methodology, circuit design, and experimental data.
We introduce UDC-3, a compact three-pulse composite control sequence designed to suppress mixed-axis coherent drift in single-qubit rotations. Standard composite pulses such as SK1 and BB1 primarily target symmetric amplitude errors, assuming that the control Hamiltonian remains aligned with the intended rotation axis. However, real quantum hardware often exhibits distorted effective rotation axes due to asymmetric calibration drift in multiple control channels. UDC-3 uses a short XYX prefix whose rotation angles are numerically optimized to maximize worst-case fidelity over two-axis drift (εx, εy ∈ [−0.12, 0.12]). Our optimized sequence improves worst-case fidelity from 66% (unoptimized UDC-3) to 98.79%, while preserving near-perfect performance at zero drift (99.91%). The optimized pulse also displays complete immunity to pure Y-axis drift, achieving 0% fidelity drop, outperforming SK1 and matching BB1 in symmetric regions while using fewer pulses. These results suggest that UDC-3 is an adaptable, hardware-aware correction primitive for coherent error suppression in near-term quantum devices. The sequence is compact, tunable, and suitable for calibration-limited platforms such as superconducting qubits, trapped ions, and spin qubits.
Abstract : This project aimed to address the most significant challenge facing the development of large-scale quantum computers: suppressing hardware error. Through this work we focused on the realization of a robust, high-fidelity Quantum Control Toolkit that is fully transportable between different quantum computing technology platforms. The techniques encapsulated herein were designed to provide qubit robustness to decoherence during memory (dynamical decoupling DD), and increase the fidelity of qubit operations undertaken in the presence of random environmental noise and control imperfections (dynamically corrected gates DCGs, and composite pulses CPs). This project has seen the demonstration of significant hardware-based improvements in quantum control fidelity along with the full experimental validation of an engineering-inspired filter-transfer function framework for quantum control.
Scalable coherent control hardware for quantum information platforms is rapidly growing in priority as their number of available qubits continues to increase. As these systems scale, more calibration steps are needed, leading to challenges with system instability as calibrated parameters drift. Moreover, the sheer amount of data required to run circuits with large depth tends to balloon, especially when implementing state-of-the-art dynamical-decoupling gates which require advanced modulation techniques. We present a control system that addresses these challenges for trapped-ion systems, through a combination of novel features that eliminate the need for manual bookkeeping, reduction in data transfer bandwidth requirements via gate compression schemes, and other automated error handling techniques. Moreover, we describe an embedded pulse compiler that applies staged optimization, including compressed intermediate representations of parsed output products, performs in-situ mutation of compressed gate data to support high-level algorithmic feedback to account for drift, and can be run entirely on chip.
Scalable coherent control hardware for quantum information platforms is rapidly growing in priority as their number of available qubits continues to increase. As these systems scale, more calibration steps are needed, leading to challenges with system instability as calibrated parameters drift. Moreover, the sheer amount of data required to run circuits with large depth tends to balloon, especially when implementing state-of-the-art dynamical-decoupling gates which require advanced modulation techniques. We present a control system that addresses these challenges for trapped-ion systems, through a combination of novel features that eliminate the need for manual bookkeeping, reduction in data transfer bandwidth requirements via gate compression schemes, and other automated error handling techniques. Moreover, we describe an embedded pulse compiler that applies staged optimization, including compressed intermediate representations of parsed output products, performs in-situ mutation of compressed gate data to support high-level algorithmic feedback to account for drift, and can be run entirely on chip.
With the advent of more quantum computing applications, it is imperative to provide developers with a set of metrics to determine how much trust they can place in the execution of their programs. In this study, we propose a novel protocol based on quantum teleportation to systematically evaluate the performance of quantum circuits and quantify their execution reliability. Our protocol consists of three parts: the payload, composed of entangled qubits with random gates applied to each wire; the bridge, which corresponds to the teleportation-inspired protocol; and an inverse payload operation, designed to return the circuit to its initial state. We validated the algorithm by elaborating its mathematical framework, followed by a comparative analysis with simulation results using Qiskit AerSimulator and ultimately through an execution on the IBM quantum and Rigetti services. A key aspect of our methodology was to set the circuit transpilation to its lowest optimization level (level 0). We recognize that even without aggressive optimization, randomly generated gates can form self-canceling sequences. As a result, our analysis correlates the pre-runtime metrics of the final, minimally-transpiled circuit (such as its actual depth and gate count) with post-runtime results (such as success rate). This approach reveals significant correlations and offers developers quantitative metrics to assess both the reliability of quantum circuit execution and scalability limitations in their applications.
Quantum teleportation is a quantum communication protocol that has been extensively studied both theoretically and experimentally. The proposed approach of using the LOCCNet framework to learn quantum teleportation protocols is investigated in this study. In the proposed protocols consider various training scenarios, including controlling gate parameters between shared entangled states, and recovery operations. To optimize the training, the parameterized quantum circuits (PQC) with training parameters is used in the LOCCNet framework, and the results show that a high-fidelity quantum teleportation protocol can be achieved even under non-ideal channels. Moreover, simulations are conducted to evaluate the effect of quantum channel noise on teleportation performance by varying the noise of entangled states and entanglement parameters under adjustable operations. The findings suggest that the trained PQC can improve system performance and potentially offer denoising capabilities. Compared with the existing LOCCNet protocol, the newly designed LOCCNet protocol has better noise immunity and can improve the fidelity and transmission success rate in specific scenarios.