Ultrafast critical ground state preparation via bang-bang protocols

Abstract

The fast and faithful preparation of the ground state of quantum systems is a challenging task but crucial for several applications in the realm of quantum-based technologies. Decoherence poses a limit to the maximum time-window allowed to an experiment to faithfully achieve such desired states. This is of particular significance in critical systems, where the vanishing energy gap challenges an adiabatic ground state preparation. We show that a bang-bang protocol, consisting of a time evolution under two different values of an externally tunable parameter, allows for a high-fidelity ground state preparation in evolution times no longer than those required by the application of standard optimal control techniques, such as the chopped-random basis quantum optimization. In addition, owing to their reduced number of variables, such bang-bang protocols are very well suited to optimization purposes, reducing the increasing computational cost of other optimal control protocols. We benchmark the performance of such approach through two paradigmatic models, namely the Landau-Zener and the Lipkin-Meshkov-Glick model. Remarkably, the critical ground state of the latter model can be prepared with a high fidelity in a total evolution time that scales slower than the inverse of the vanishing energy gap.

arXiv comment7 pages and 9 figs; comments welcome!

References in corpus (81)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Entanglement in quantum critical phenomena
• Scaling of Entanglement close to a Quantum Phase Transitions
• Dynamical suppression of decoherence in two-state quantum systems
• Adiabatic Quantum Computing
• Entanglement in a simple quantum phase transition
• Shortcuts to adiabaticity: concepts, methods, and applications
• Cosmological Experiments in Condensed Matter Systems
• Dynamics of a Quantum Phase Transition
• Training Schrödinger's cat: quantum optimal control
• The European Quantum Technologies Roadmap
• Quantum Search by Local Adiabatic Evolution
• Quantum speed limits: from Heisenberg's uncertainty principle to optimal quantum control
• Direct observation of dynamical quantum phase transitions in an interacting many-body system
• Quantum speed limit for physical processes
• Optimal Control at the Quantum Speed Limit
• Universal adiabatic dynamics across a quantum critical point
• Quantum Phase Transition and Universal Dynamics in the Rabi model
• Universality of Entropy Scaling in 1D Gap-less Models
• Optimal control technique for Many Body Quantum Systems dynamics
• Classical bifurcation at the transition from Rabi to Josephson dynamics
• Chopped random-basis quantum optimization
• Quantum limits to dynamical evolution
• Universality of Phase Transition Dynamics: Topological Defects from Symmetry Breaking
• Quantum criticality as a resource for quantum estimation
• Quantum Brachistochrone
• Reinforcement Learning in Different Phases of Quantum Control
• Second order gradient ascent pulse engineering
• Finite-Size Scaling Exponents of the Lipkin-Meshkov-Glick Model
• Exact spectrum of the Lipkin-Meshkov-Glick model in the thermodynamic limit and finite-size corrections
• Critical Quantum metrology with a finite-component quantum phase transition
• Trade-off between speed and cost in shortcuts to adiabaticity
• Driving at the quantum speed limit: Optimal control of a two-level system
• Quench dynamics near a quantum critical point
• The Thermodynamical Limit of the Lipkin-Meshkov-Glick Model
• Density of kinks after a quench: When symmetry breaks, how big are the pieces?
• Energy-time uncertainty relation for driven quantum systems
• Genuine quantum correlations in quantum many-body systems: a review of recent progress
• Adiabatic tracking of quantum many-body dynamics
• Quantum critical metrology
• Optimal non-linear passage through a quantum critical point
• Efficient variational simulation of non-trivial quantum states
• Dressing the chopped-random-basis optimization: a bandwidth-limited access to the trap-free landscape
• Optimal control of complex atomic quantum systems
• Large N Scaling Behavior of the Lipkin-Meshkov-Glick Model
• Probing the Dynamics of Superradiant Quantum Phase Transition in a Single Trapped-Ion
• Deep Reinforcement Learning for Quantum Gate Control
• Krotov: A Python implementation of Krotov's method for quantum optimal control
• Adiabatic quantum dynamics of the Lipkin-Meshkov-Glick model
• Orthogonality Catastrophe as a Consequence of the Quantum Speed Limit
• Entanglement entropy in collective models
• Fast quasi-adiabatic dynamics
• Global optimization of quantum dynamics with AlphaZero deep exploration
• Speeding up critical system dynamics through optimized evolution
• Dynamical critical scaling of long-range interacting quantum magnets
• Quantum speed limits and the maximal rate of information production
• Quantum Optimal Control in a Chopped Basis: Applications in Control of Bose-Einstein Condensates
• Modified Newton-Raphson GRAPE methods for optimal control of spin systems
• Automatic spin-chain learning to explore the quantum speed limit
• Experimental Performance of a Quantum Simulator: Optimizing Adiabatic Evolution and Identifying Many-Body Ground States
• Criticality revealed through quench dynamics the Lipkin-Meshkov-Glick model
• New dynamical scaling universality for quantum networks across adiabatic quantum phase transitions
• Universal anti-Kibble-Zurek scaling in fully-connected systems
• Bang-bang shortcut to adiabaticity in the Dicke model as realized in a Penning trap experiment
• Universal dynamics of inhomogeneous quantum phase transitions: suppressing defect formation
• Neural-network-designed pulse sequences for robust control of singlet-triplet qubits
• Irreversible processes without energy dissipation in an isolated Lipkin-Meshkov-Glick model
• Kibble-Zurek scaling of the irreversible entropy production
• Quantum Optimal Control: Landscape Structure and Topology
• Geometric quantum speed limits and short-time accessibility to unitary operations
• Testing quantum adiabaticity with quench echo
• Ultrafast Variational Simulation of Non-trivial Quantum States with Long Range Interactions
• Topological relics of symmetry breaking: Winding numbers and scaling tilts from random vortex-antivortex pairs
• Quantum state engineering by shortcuts-to-adiabaticity in interacting spin-boson systems
• Suppressing defect production during passage through a quantum critical point
• Nonadiabatic dynamics of the excited states for the Lipkin-Meshkov-Glick model
• Quantum control with noisy fields: computational complexity vs. sensitivity to noise
• Bang-bang shortcut to adiabaticity in trapped ion quantum simulators
• Optimization of Pulses with Low Bandwidth for Improved Excitation of Multiple-Quantum Coherences in NMR of Quadrupolar Nuclei
• Push-Pull Optimization of Quantum Controls
• Quantum mechanics and speed limit of ultrafast local control in spin chains

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• Non-Gaussian superradiant transition via three-body ultrastrong coupling
• Improved iterative quantum algorithm for ground-state preparation
• Critical Quantum Sensing: a tutorial on parameter estimation near quantum phase transitions
• Lower bounds on the number of rounds of the quantum approximate optimization algorithm required for guaranteed approximation ratios
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