# Optimizing for an arbitrary perfect entangler. II. Application

@article{Goerz2015OptimizingFA,
title={Optimizing for an arbitrary perfect entangler. II. Application},
author={Michael Goerz and Giulia Gualdi and Daniel M Reich and Christiane P. Koch and Felix Motzoi and K. Birgitta Whaley and Jivr'i Vala and Matthias M. Muller and Simone Montangero and Tommaso Calarco},
journal={Physical Review A},
year={2015},
volume={91},
pages={062307}
}
• Published 23 December 2014
• Physics
• Physical Review A
The difficulty of an optimization task in quantum information science depends on the proper mathematical expression of the physical target. Here we demonstrate the power of optimization functionals targeting an arbitrary perfect two-qubit entangler, which allow generation of a maximally entangled state from some initial product state. We show for two quantum information platforms of current interest, i.e., nitrogen vacancy centers in diamond and superconducting Josephson junctions, that an…
21 Citations

## Figures and Tables from this paper

QUANTUM ENTANGLEMENT AND OPTIMAL CONTROL
Optimal control theory is a powerful tool for improving figures of merit in quantum information tasks. I will present recent results on applications of optimal control in quantum information
Local gradient optimization of modular entangling sequences
• Physics, Computer Science
Physical Review A
• 2018
A gradient-based optimization approach is used to find single-qubit rotations which can be interleaved between applications of a noisy nonlocal gate to dramatically suppress arbitrary logical errors, while steering the evolution operator towards the perfectly entangling subset of SU(4) gates.
Optimal control of superconducting gmon qubits using Pontryagin's minimum principle: Preparing a maximally entangled state with singular bang-bang protocols
• Mathematics
Physical Review A
• 2018
We apply the theory of optimal control to the dynamics of two “Gmon” qubits, with the goal of preparing a desired entangled ground state from an initial unentangled one. Given an initial state, a
Optimized cross-resonance gate for coupled transmon systems
• Physics
• 2018
The cross-resonant gate is an entangling gate for fixed frequency superconducting qubits introduced for untunable qubits. While being simple and extensible, it suffers from long duration and limited
Optimal control methods for quantum gate preparation: a comparative study
• Engineering
Quantum Inf. Process.
• 2019
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.
Dissipative quantum dynamics and optimal control using iterative time ordering: an application to superconducting qubits
• Physics
The European Physical Journal B
• 2018
Abstract We combine a quantum dynamical propagator that explicitly accounts for quantum mechanical time ordering with optimal control theory. After analyzing its performance with a simple model, we
Efficient Quantum Gate Discovery with Optimal Control
• Computer Science
2021 IEEE International Conference on Quantum Computing and Engineering (QCE)
• 2021
This work proposes a framework for designing objective functions that permit novel gate designs such as echo pulses or locally-equivalent gates that lead to higher fidelity controls in fewer optimization iterations than obtainable by traditional objective functions.
Controlling open quantum systems: tools, achievements, and limitations.
• C. Koch
• Physics
Journal of physics. Condensed matter : an Institute of Physics journal
• 2016
Recent advances in optimal control methodology that allow typical tasks in device operation for open quantum systems to be tackled are reviewed and examples of relaxation-optimized dynamics are discussed.
Control and coherence time enhancement of the 0–π qubit
• Physics
New Journal of Physics
• 2019
Kitaev's 0-$\pi$ qubit encodes quantum information in two protected, near-degenerate states of a superconducting quantum circuit. In a recent work, we have shown that the coherence times of a
Hybrid optimization schemes for quantum control
• Physics
• 2015
A two-stage optimization scheme to significantly speed up convergence and achieve simpler controls is proposed, showing that a combination of Nelder-Mead simplex and Krotov’s method yields considerably better results than either one of the two methods alone.

## References

SHOWING 1-10 OF 101 REFERENCES
Quantum Computation and Quantum Information
• Physics, Computer Science
• 2000
This chapter discusses quantum information theory, public-key cryptography and the RSA cryptosystem, and the proof of Lieb's theorem.
Opt
• Computer Science
• 2017
A new language, Opt, is proposed for writing these objective functions over image- or graph-structured unknowns concisely and at a high level and automatically transforms these specifications into state-of-the-art GPU solvers based on Gauss-Newton or Levenberg-Marquardt methods.
Nature
• R. Rosenfeld
• Medicine
• 2009
Phys
• Rev. A 91, 062306
• 2015
and C
• P. Koch
• 2014
Phys
• 136, 104103
• 2012
Phys
• Rev. A 84, 042315
• 2011
Phys. Rev. A
• Phys. Rev. A
• 2011
Phys
• Rev. A 67, 042313
• 2003
#p
• Computer Science
Quantum Inf. Comput.
• 2017