Optimisation of diamond quantum processors

Abstract

Diamond quantum processors consisting of a nitrogen-vacancy (NV) centre and surrounding nuclear spins have been the key to significant advancements in room-temperature quantum computing, quantum sensing and microscopy. The optimisation of these processors is crucial for the development of large-scale diamond quantum computers and the next generation of enhanced quantum sensors and microscopes. Here, we present a full model of multi-qubit diamond quantum processors and develop a semi-analytical method for designing gate pulses. This method optimises gate speed and fidelity in the presence of random control errors and is readily compatible with feedback optimisation routines. We theoretically demonstrate infidelities approaching $\sim 10^{-5}$ for single-qubit gates and established evidence that this can also be achieved for a two-qubit CZ gate. Consequently, our method reduces the effects of control errors below the errors introduced by hyperfine field misalignment and the unavoidable decoherence that is intrinsic to the processors. Having developed this optimal control, we simulated the performance of a diamond quantum processor by computing quantum Fourier transforms. We find that the simulated diamond quantum processor is able to achieve fast operations with low error probability.

arXiv commentPublished version. Updated references, additional analysis for the infidelities of CZ gate. Two new appendices on discussing the effects of time-ordering in the quantum evolution and examining the effects of the secular approximation and hyperfine field misalignments on gate fidelities. Adjusted the discussions and claims accordingly

References in corpus (48)

• Surface codes: Towards practical large-scale quantum computation
• The nitrogen-vacancy colour centre in diamond
• Experimental loophole-free violation of a Bell inequality using entangled electron spins separated by 1.3 km
• Heralded entanglement between solid-state qubits separated by 3 meters
• Universal dynamical decoupling of a single solid-state spin from a spin bath
• High precision nano scale temperature sensing using single defects in diamond
• Quantum error correction in a solid-state hybrid spin register
• Roads towards fault-tolerant universal quantum computation
• Fault-Tolerant Quantum Dynamical Decoupling
• Room temperature entanglement between distant single spins in diamond
• Scalable quantum register based on coupled electron spins in a room temperature solid
• A 10-qubit solid-state spin register with quantum memory up to one minute
• Universal control and error correction in multi-qubit spin registers in diamond
• Optimal control technique for Many Body Quantum Systems dynamics
• Entanglement Distillation between Solid-State Quantum Network Nodes
• Decoherence-protected quantum gates for a hybrid solid-state spin register
• Chopped random-basis quantum optimization
• Universal Control of Decoupled Quantum Systems
• High fidelity spin entanglement using optimal control
• Detection and control of individual nuclear spins using a weakly coupled electron spin
• One-second coherence for a single electron spin coupled to a multi-qubit nuclear-spin environment
• Dynamical Decoupling of a single electron spin at room temperature
• Experimental fault-tolerant universal quantum gates with solid-state spins under ambient conditions
• Repeated quantum error correction on a continuously encoded qubit by real-time feedback
• Scalable Architecture for a Room Temperature Solid-State Quantum Information Processor
• Decoherence and dynamical decoupling control of nitrogen-vacancy center electron spins in nuclear spin baths
• Bang-bang control of fullerene qubits using ultra-fast phase gates
• Detection of a single fundamental charge with nanoscale resolution in ambient conditions using the NV${}^{-}$ center in diamond
• Procedures for Converting among Lindblad, Kraus and Matrix Representations of Quantum Dynamical Semigroups
• Quantum metrology enhanced by repetitive quantum error correction
• Quantum Simulation of Helium Hydride in a Solid-State Spin Register
• Room-temperature implementation of the Deutsch-Jozsa algorithm with a single electronic spin in diamond
• Enhanced solid-state multi-spin metrology using dynamical decoupling
• Measuring Controlled-NOT and two-qubit gate operation
• Comparison of dynamical decoupling protocols for a nitrogen-vacancy center in diamond
• Protected quantum computing: Interleaving gate operations with dynamical decoupling sequences
• Protecting a diamond quantum memory by charge state control
• Precise ultra fast single qubit control using optimal control pulses
• Nonvolatile quantum memory enables sensor unlimited nanoscale spectroscopy of finite quantum systems
• Dephasing mechanisms of diamond-based nuclear-spin memories for quantum networks
• Noise-resilient quantum evolution steered by dynamical decoupling
• Ultrafast entangling gates between nuclear spins using photo-excited triplet states
• A Data-Driven Gradient Algorithm for High-Precision Quantum Control
• Room-temperature high-speed nuclear-spin quantum memory in diamond
• Experimental Adiabatic Quantum Factorization under Ambient Conditions Based on a Solid-State Single Spin System
• Direct measurement of topological numbers with spins in diamond
• Nuclear Quantum-Assisted Magnetometer
• Experimental Hamiltonian Learning of An 11-qubit Solid-State Quantum Spin Register

Cited by in corpus (8)

• Introduction to Quantum Optimal Control for Quantum Sensing with Nitrogen-Vacancy Centers in Diamond
• Noisy intermediate-scale quantum computers
• Diamond Integrated Quantum Photonics: A Review
• Room-temperature control and electrical readout of individual nitrogen-vacancy nuclear spins
• Performance of quantum registers in diamond in the presence of spin impurities
• Limits to Quantum Gate Fidelity from Near-Field Thermal and Vacuum Fluctuations
• Semiempirical $\text{ab initio}$ modeling of bound states of deep defects in semiconductor quantum technologies
• Anisotropic electron-nuclear interactions in a rotating quantum spin bath