Exact Diagonalization Study of Double Quantum Dot System in Zero-bandwidth Limit

Authors

  • Haroon . Department of Physics, Jamia Millia Islamia (Central University), New Delhi 110025
  • M. A.H. Ahsan Department of Physics, Jamia Millia Islamia (Central University), New Delhi 110025

DOI:

https://doi.org/10.26713/jamcnp.v2i3.339

Keywords:

Double quantum dot, Spin-spin correlation, Zero-bandwidth limit

Abstract

Using exact diagonalization, we study double quantum dot system with one of the dots attached to the ideal leads acting as source and drain in T-shaped geometry. The leads are incorporated in zero-bandwidth limit by replacing their band structures with one level coinciding with Fermi levels in the respective leads. For the half-filled case, the spin-spin correlation for the dots are calculated numerically at zero as well as finite temperatures. At zero temperature, an antiferromagnetic correlation between the dots is observed for finite values of interdot tunneling matrix-element. The antiferromagnetic correlation between the dots changes  remarkably for large values of ondot Coulomb interaction both at zero as well as finite temperatures. The spin-spin correlation between the dots is significantly reduced even for small values of the inderdot Coulomb interaction compared to the ondot Coulomb interaction. At a small value of temperature, the spin-spin correlation between the dots exhibits a (negative) maximum due to contributions coming from thermal excitations to low-lying states.

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References

Wu, Jiang, Wang, Zhiming M., Quantum Dot Molecules, Springer-Verlag, New York, 2014.

K. Shiraishi, H. Tamura and H. Takayanagi, Appl. Phys. Lett. 78, 3702 (2001).

D. Loss and D.P. DiVincenzo, Phys. Rev. A, 57, 120 (1998).

Wang, Zhiming M., Quantum Dot Devices, Springer-Verlag New York, 2012.

A.D. Yoffe, Adv. Phys., 2001, 50, 1 (2001).

W.G. van der Wiel, S. De Franceschi, J.M. Elzerman, T. Fujisawa, S. Tarucha and L.P. Kouwenhoven, Review of Modern Physics, 75, 1 (2003).

R. Allub and C.R. Proetto, Physical Review B, 62, 10923 (2000).

R. Allub and C.R. Proetto, Solid State Communications, 117, 429-434 (2001).

R. Allub, Physical Review B 67, 144416 (2003).

L.P. Kouwenhoven, D.G. Austing and S. Traucha, Rep. Prog. Phys., 64, 701 (2001).

S. Alexander and P.W. Anderson, Phys. Rev. A, 133, 1594 (1964).

B.R. Bulka and T. Kostyrko, Physical Review B, 70, 205333 (2004).

R. Allub, J. Phys. Condens. Matter, 20, 445208 (2008).

B.R. Alascio, R. Allub and A. Aligia, J. Phys. C: Solid St. Phys., 13, 2869-2879 (1980).

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Published

2015-12-28
CITATION

How to Cite

., H., & Ahsan, M. A. (2015). Exact Diagonalization Study of Double Quantum Dot System in Zero-bandwidth Limit. Journal of Atomic, Molecular, Condensed Matter and Nano Physics, 2(3), 187–193. https://doi.org/10.26713/jamcnp.v2i3.339

Issue

Vol. 2 No. 3 (2015)

Section

Research Article

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