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Squeezing Dynamics In A Nanowire System

Science Contributor
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October 15, 2018
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SEM image of epitaxial nanowire heterostructures grown from catalytic gold nanoparticles. Nanowires by Thomas Mårtensson[1]; SEM image by Kristian Mølhave. This illustration was made for the Opensource Handbook of Nanoscience and Nanotechnology. Licensed under CC-BY 2.5 https://creativecommons.org/licenses/by/2.5/deed.en

Nanowires provide novel mechanisms for scaling down semiconductor electronics [1]. Semiconducting nanowires have electronically switchable characteristics suitable for simple readout that is appropriate for sensing. Since photoelectric signals from nanosensors can be immediately combined and routed to the external world, they can efficiently be coupled into miniaturized systems [2].

Recently, the physical characteristics of quantum wires employing semiconductor materials have been investigated due to their potential for realizing quantum computing devices [3-5]. The spin and the orbital motion of the electron in a nanowire system play the role of the atom-light interaction in quantum optics [6]. Therefore, we can study quantum properties such as entropy squeezing in a nanowire system, which has been explored in atom-light interactions.

The importance of atomic squeezing for developing quantum applications and especially in quantum information theory has been previously studied. These studies demonstrated the operation of atomic squeezing and its impact on quantum cryptography, dense coding, and teleportation [7-10]. Atomic squeezing is typically quantified through variance squeezing using the famous Heisenberg uncertainty relation (HUR) [11]. The entropic uncertainty relation (EUR) is a different approach for quantifying information squeezing [12-16]. Entropy squeezing in the Jaynes-Cummings system and its generalizations have been analyzed by applying the EUR [17-20].

The influence of magnetic fields on the characteristics of nanowire systems has been previously investigated by many research groups but their impact on the squeezing of the quantum states has not been analyzed before.  Therefore, we investigated the influence of squeezing in a novel model made up of a nanowire with Rashba spin-orbit interaction in the presence of strong and weak magnetic fields for different initial conditions of the system [16].

Our results demonstrated that the entropy squeezing is a more sensitive measure of information squeezing as opposed to the standard variance squeezing. Additionally, the influences of spin-orbit interaction strength and the initial state of the system on the information entropy squeezing for various concentrations of the magnetic field have been investigated. The results prove that there is a robust correlation between the spin-orbit interaction and the strength of entropy squeezing. When there is an increase in the strength of the spin-orbit interaction, the influence of the entropy squeezing is increased, and vice versa. Also, there is a relation between the initial state and the number of squeezed elements.

If the system starts into an excited state, the squeezing will mainly happen in individual element or quadrature. But, when the system begins in a superposition state, the squeezing can happen in both quadratures. Consequently, we have identified unique techniques to manage the strength and the element of entropy squeezing in a nanowire system. These techniques could potentially be used in future quantum information technology applications.

These findings are described in the article entitled Squeezing dynamics of nanowire system with spin-orbit interaction, recently published in the journal Scientific Reports. This work was conducted by R. I. Mohamed and O. H. El-Kalaawy from Beni-Suef University, Ahmed Farouk and S. Ghose from Wilfrid Laurier University, A. H. Homid and Abdel-Haleem Abdel-Aty from Al-Azhar University, and M. Abdel-Aty from Sohag University.

References: 

  1. Nagashima, K., & Yanagida, T. (2015). Oxide nanowires for nonvolatile memory applications. In Magnetic Nano-and Microwires (pp. 489-524).
  2. Dahman, Y. (2017). Nanotechnology and Functional Materials for Engineers. Elsevier.
  3. Bandyopadhyay, S. Physics of nanostructured solid state devices. Springer Science and Business Media (2012).
  4. Lahon, S., Jha, P. K. & Mohan, M. Nonlinear interband and intersubband transitions in quantum dots for multiphoton photodetectors. Journal of Applied Physics 109(5), 054311 (2011).
  5. Lahon, S., Gambhir, M., Jha, P. K. & Mohan, M. Multiphoton excitation of disc shaped quantum dot in presence of laser (THz) and magnetic field for bioimaging. physica status solidi (b) 247(4), 962–967 (2010).
  6. Debald, S. and Kramer, B. (2005). Rashba effect and magnetic field in semiconductor quantum wires. Physical Review B, 71(11), 115322.
  7. Banerjee, S., Dan, A. & Chakravorty, D. Review synthesis of conducting nanowires. Journal of materials science 37(20), 4261–4271 (2002).
  8. Ihn, T. Semiconductor Nanostructures: Quantum states and electronic transport. Oxford University Press (2010).
  9. Bryant, G. W. & Solomon, G. (Eds). Optics of quantum dots and wires. Artech House Publishers (2005).
  10. Debald, S. & Kramer, B. Rashba effect and magnetic field in semiconductor quantum wires. Physical Review B 71(11), 115322 (2005).
  11. El-Orany, F. A., Wahiddin, M. R. B. and Obada, A. S. (2008). Single-atom entropy squeezing for two two-level atoms interacting with a single-mode radiation field. Optics Communications, 281(10), 2854-2863.
  12. Heisenberg, W. (1927). ber den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik. Zeitschrift fur Physik, 43, 172-198.
  13. Fang, M. F., Zhou, P. and Swain, S. (2000). Entropy squeezing for a two-level atom. Journal of Modern Optics, 47(6), 1043-1053.
  14. Hirschman, I. I. (1957). A note on entropy. American journal of mathematics, 79(1), 152156.
  15. Bialynicki-Birula, I. and Mycielski, J. (1975). Uncertainty relations for information entropy in wave mechanics. Communications in Mathematical Physics, 44(2), 129-132.
  16. Deutsch, D. (1983). Uncertainty in quantum measurements. Physical Review Letters, 50(9), 631.
  17. Hillery, M. (2000). Quantum cryptography with squeezed states. Physical Review A, 61(2), 022309.
  18. Ban, M. (1999). Quantum dense coding via a two-mode squeezed-vacuum state. Journal of Optics B: Quantum and Semiclassical Optics, 1(6), L9.
  19. Abdel-Aty, M. (2002). Quantum Information and Entropy Squeezing of a Nonlinear Multi quantum JC Model. Communications in Theoretical Physics, 37(6), 723.
  20. Abdalla, M. S., Lashin, E. and Sadiek, G. (2007). Entropy and variance squeezing for time dependent two-coupled atoms in an external magnetic field. Journal of Physics B: Atomic, Molecular and Optical Physics, 41(1), 015502.
  21. Mohamed, R. I., Farouk, A., Homid, A. H., El-Kalaawy, O. H., Abdel-Aty, A. H., Abdel-Aty, M., & Ghose, S. (2018). Squeezing dynamics of a nanowire system with spin-orbit interaction. Scientific reports, 8(1), 10484.
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