# 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} }

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…

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## 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

- MedicineOtolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
- 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