Optimal control for fast and high-fidelity quantum gates in coupled superconducting flux qubits

  title={Optimal control for fast and high-fidelity quantum gates in coupled superconducting flux qubits},
  author={Shan Huang and Hsi-Sheng Goan},
  journal={Physical Review A},
We apply the quantum optimal control theory based on the Krotov method to implement single-qubit $X$ and $Z$ gates and two-qubit CNOT gates for inductively coupled superconducting flux qubits with fixed qubit transition frequencies and fixed off-diagonal qubit-qubit coupling. Our scheme that shares the same advantage of other directly coupling schemes requires no additional coupler subcircuit and control lines. The control lines needed are only for the manipulation of individual qubits (e.g., a… 

Figures and Tables from this paper

Realization of qudits in coupled potential wells
The theoretical grounds underlying the double-well qubit dynamics are revisited, then novel extensions of these principles are suggested to a triple-well qutrit with periodic boundary conditions, followed by a general d-well analysis of qudits.
Optimal control methods for quantum gate preparation: a comparative study
From the numerical simulations, it is observed that GOAT achieves better results as compared to Krotov, GRAPE and CRAB, in terms of minimum infidelity, algorithmic simplicity and analyticity.
Lyapunov Based Control for One Qubit Quantum Gates in Coherence Vector Formulation
The design of one qubit quantum gates with Lyapunov-based method is studied in this paper. Firstly, one qubit quantum control system is described in the coherence vector formation, then two types of
Quantum criticality and state engineering in the simulated anisotropic quantum Rabi model
Promising applications of the anisotropic quantum Rabi model (AQRM) in broad parameter ranges are explored, which is realized with superconducting flux qubits simultaneously driven by two-tone
Fast Quantum Communication in Linear Networks
If there is no restriction on the size of the linear coupling between two oscillators, then there exist control protocols that will swap their respective states with high fidelity within a time much less than a single oscillation period, and standard gradient search methods fail to find these fast protocols.
Learning robust pulses for generating universal quantum gates
Numerical results show that the learned robust control fields are insensitive to disturbances, uncertainties and fluctuations during the process of realizing universal quantum gates.
Learning robust control for generating universal quantum gates
Abstract. Constructing a set of universal quantum gates is a fundamental task for quantum computation. The existence of noises, disturbances and fluctuations is unavoidable during the process of
Geodesic paths and topological charges in quantum systems
This dissertation focuses on one question: how should one drive an experimentally prepared state of a generic quantum system into a di↵erent target-state, simultaneously minimizing energy dissipation
Algorithm for solving unconstrained unitary quantum brachistochrone problems
We introduce an iterative method to search for time-optimal Hamiltonians that drive a quantum system between two arbitrary, and in general mixed, quantum states. The method is based on the idea of
Many-Body Quantum State Control in the Presence of Environmental Noise
Inspired by the striking phenomenon that cats can land on their feet when they fall, we consider a simple model to simulate a quantum version of the orientation change of a falling cat. Our model


Time-dependent quantum molecular dynamics
Variable Time-Step Integration for Intense Field Effects C. Cerjan, R. Kosloff. Adiabatic and Diabatic Basis Sets in Molecular Calculations R. Cimiraglia. Classical and Quantum Mechanics of the
We discuss the distribution function for the current noise in Quantum point contacts. Special interest is paid to contact of a superconductor with a normal metal. A new derivation of the
Statistical packages have been used for decades to analyze large datasets or to perform mathematically intractable statistical methods. These packages are not capable of working with random variables
  • Phys. 7, 565-570
  • 2011
  • Rev. Lett. 96, 067003
  • 2006
  • Rev. A 89, 062310
  • 2014
  • Schulte- Herbrüggen J. Biamonte, and J. Wrachtrup, Nat. Commun. 5, 3371
  • 2014
New J
  • Phys. 14, 073041
  • 2012
  • Rev. Lett. 109, 060501
  • 2012
  • Rev. Lett. 108, 180501
  • 2012