Quantum control methods for robust entanglement of trapped ions

Abstract

A major obstacle in the way of practical quantum computing is achieving scalable and robust high-fidelity entangling gates. To this end, quantum control has become an essential tool, as it can make the entangling interaction resilient to sources of noise. Nevertheless, it may be difficult to identify an appropriate quantum control technique for a particular need given the breadth of work pertaining to robust entanglement. To this end, we attempt to consolidate the literature by providing a non-exhaustive summary and critical analysis. The quantum control methods are separated into two categories: schemes which extend the robustness to (i) spin or (ii) motional decoherence. We choose to focus on extensions of the ${\sigma }_x\otimes {\sigma }_x$ Molmer-Sorensen interaction using microwaves and a static magnetic field gradient. Nevertheless, some of the techniques discussed here can be relevant to other trapped ion architectures or physical qubit implementations. Finally, we experimentally realize a proof-of-concept interaction with simultaneous robustness to spin and motional decoherence by combining several quantum control methods presented in this manuscript.

arXiv comment29 pages, 23 figures

References in corpus (84)

• Dynamical Decoupling of Open Quantum Systems
• Dynamical suppression of decoherence in two-state quantum systems
• Quantum computation with ions in thermal motion
• Fault-tolerant quantum computation with high threshold in two dimensions
• Entanglement and quantum computation with ions in thermal motion
• High-fidelity two-qubit quantum logic gates using trapped calcium-43 ions
• High-fidelity quantum logic gates using trapped-ion hyperfine qubits
• Keeping a Quantum Bit Alive by Optimized $\pi$-Pulse Sequences
• Optimized Dynamical Decoupling in a Model Quantum Memory
• High-fidelity preparation, gates, memory and readout of a trapped-ion quantum bit
• Fault-Tolerant Quantum Dynamical Decoupling
• Demonstration of the trapped-ion quantum-CCD computer architecture
• High-Fidelity Universal Gate Set for ${}^9$Be${}^{+}$ Ion Qubits
• Towards fault-tolerant quantum computing with trapped ions
• Benchmarking an 11-qubit quantum computer
• Ion-trap quantum logic using long-wavelength radiation
• Unification of Dynamical Decoupling and the Quantum Zeno Effect
• Single ion-qubit exceeding one hour coherence time
• Blueprint for a microwave trapped-ion quantum computer
• Fast quantum logic gates with trapped-ion qubits
• Quantum Gates and Memory using Microwave Dressed States
• Robust dynamical decoupling
• Trapped-ion quantum logic gates based on oscillating magnetic fields
• Robust dynamical decoupling with concatenated continuous driving
• Optimal quantum control of multi-mode couplings between trapped ion qubits for scalable entanglement
• Dynamical decoupling sequence construction as a filter-design problem
• High-fidelity laser-free universal control of two trapped ion qubits
• Entangled Mechanical Oscillators
• High-Fidelity Bell-State Preparation with ${}^{40}$Ca${}^{+}$ Optical Qubits
• Assessing the progress of trapped-ion processors towards fault-tolerant quantum computation
• Rotating-frame relaxation as a noise spectrum analyzer of a superconducting qubit undergoing driven evolution
• High-fidelity trapped-ion quantum logic using near-field microwaves
• Experimental noise filtering by quantum control
• Scalable global entangling gates on arbitrary ion qubits
• Robust two-qubit gates in a linear ion crystal using a frequency-modulated driving force
• Arbitrary quantum control of qubits in the presence of universal noise
• Trapped-ion quantum logic with global radiation fields
• Deterministic entanglement of ions in thermal states of motion
• Designer Spin Pseudomolecule Implemented with Trapped Ions in a Magnetic Gradient
• Robust Trapped-Ion Quantum Logic Gates by Continuous Dynamical Decoupling
• Optimizing a Dynamical Decoupling Protocol for Solid-State Electronic Spin Ensembles in Diamond
• Robust entanglement gates for trapped-ion qubits
• Efficient Arbitrary Simultaneously Entangling Gates on a trapped-ion quantum computer
• Coherent Error Suppression in Multi-Qubit Entangling Gates
• Hybrid quantum logic and a test of Bell's inequality using two different atomic isotopes
• Robust and resource-efficient microwave near-field entangling ${}^9$Be${}^{+}$ gate
• Two-qubit entangling gates within arbitrarily long chains of trapped ions
• High-fidelity Two-qubit Gates Using a MEMS-based Beam Steering System for Individual Qubit Addressing
• Phase-modulated decoupling and error suppression in qubit-oscillator systems
• A trapped-ion based quantum byte with $10^{-5}$ next-neighbour cross-talk
• Resilient entanglement gates for trapped ions
• Phase-modulated entangling gates robust to static and time-varying errors
• Continuously decoupling single-qubit operations from a perturbing thermal bath of scalar bosons
• Demonstration of a dressed-state phase gate for trapped ions
• Protecting conditional quantum gates by robust dynamical decoupling
• Efficient preparation and detection of microwave dressed-state qubits and qutrits with trapped ions
• Simple Manipulation of a Microwave Dressed-State Ion Qubit
• High fidelity state preparation and measurement of ion hyperfine qubits with I > 1/2
• Theory of robust multi-qubit non-adiabatic gates for trapped-ions
• Effect of pulse error accumulation on dynamical decoupling of the electron spins of phosphorus donors in silicon
• Continuous dynamical decoupling utilizing time-dependent detuning
• Experimental realization of time-dependent phase-modulated continuous dynamical decoupling
• Entangling an arbitrary pair of qubits in a long ion crystal
• Versatile ytterbium ion trap experiment for operation of scalable ion trap chips with motional heating and transition frequency measurements
• Versatile laser-free trapped-ion entangling gates
• High fidelity quantum gates of trapped ions mediated by a dissipative bus mode
• Reducing sequencing complexity in dynamical quantum error suppression by Walsh modulation
• Fast dynamical decoupling of the Molmer-Sorensen entangling gate
• Versatile microwave-driven trapped ion spin system for quantum information processing
• Generation of high-fidelity quantum control methods for multi-level systems
• Batch Optimization of Frequency-Modulated Pulses for Robust Two-qubit Gates in Ion Chains
• General scheme for the construction of a protected qubit subspace
• Driven Geometric Phase Gates with Trapped Ions
• Generation of spin-motion entanglement in a trapped ion using long-wavelength radiation
• Numeric optimization for configurable, parallel, error-robust entangling gates in large ion registers
• Driven dynamics and rotary echo of a qubit tunably coupled to a harmonic oscillator
• Pulsed Dynamical Decoupling for Fast and Robust Two-Qubit Gates on Trapped Ions
• Laser-free trapped-ion entangling gates with simultaneous insensitivity to qubit and motional decoherence
• Experimental Bayesian calibration of trapped ion entangling operations
• Universal Set of Gates for Microwave Dressed-State Quantum Computing
• Strong-coupling quantum logic of trapped ions
• Hybrid Microwave Radiation Patterns for High-Fidelity Quantum Gates with Trapped Ions
• Optimal digital dynamical decoupling for general decoherence via Walsh modulation
• Trapped-Ion Entangling Gates Robust Against Qubit Frequency Errors

Cited by in corpus (6)

• Realizing quantum gates with optically-addressable ${}^{171}$Yb${}^{+}$ ion qudits
• Engineering dynamically decoupled quantum simulations with trapped ions
• Designing Filter Functions of Frequency-Modulated Pulses for High-Fidelity Two-Qubit Gates in Ion Chains
• Robust two-qubit trapped ions gates using spin-dependent squeezing
• Quadrupole transitions and quantum gates protected by continuous dynamic decoupling
• Robust Oscillator-Mediated Phase Gates Driven by Low-Intensity Pulses