Applied Nanoscience

, Volume 9, Issue 8, pp 1685–1693 | Cite as

Tunable spin-polarized transport through a side-gated double quantum dot molecular junction in the Coulomb blockade regime

  • Yebin Dai
  • Xue-Feng WangEmail author
  • P. Vasilopoulos
  • Yu-Shen Liu
Original Article


Based on nonequilibrium Green’s function method, we investigate spin-polarized transport properties of a side-gated double quantum dot (DQD) system in the Coulomb blockade regime under a magnetic field and an electric or thermal bias. The charge and spin currents oscillate frequently and can change sign upon varying gate voltage \({V_{\text{G}}}\) if the electric bias is spin–dependent. Under a thermal bias, besides the charge- and spin-current oscillations with \({V_{\text{G}}}\), a pure spin current appears at the electron–hole symmetry point. Importantly, its sign can be controlled by the magnetic field above a “critical” strength. In addition, the charge- and spin-Seebeck coefficients oscillate nontrivially depending on \({V_{\text{G}}}\), \(B\), and the tunnel coupling. Finally, we also study the spin-polarized transport properties of the DQD system effects under simultaneously applying an electric and a thermal bias.


Double quantum dots Electric and thermal bias Charge and spin currents Coulomb blockade Charge- and spin-Seebeck coefficients 



This work was supported by National Natural Science Foundation of China (Grant Nos 61674110 and 91121021 and 6167204) and by the Canadian NSERC Grant No. OGP0121756.

Compliance with ethical standards

Conflict of interest

None of the authors of this manuscript have any competing interests.


  1. Aguado R, Langreth DC (2000) Out-of-equilibrium Kondo effect in double quantum dots. Phys Rev Lett 85:1946CrossRefGoogle Scholar
  2. Alivisatos P (1996) Semiconductor clusters, nanocrystals, and quantum dots. Science 271:5251CrossRefGoogle Scholar
  3. Aono T, Eto M (2001) Kondo resonant spectra in coupled quantum dots. ibid 63:125327Google Scholar
  4. Baltin R, Gefen Y, Hackenbroich G, Weidenmuller HA (1999) Correlations of conductance peaks and transmission phases in deformed quantum dots. Eur Phys J B. 10:119CrossRefGoogle Scholar
  5. Beenakker WJ (1991) Theory of Coulomb-blockade oscillations in the conductance of a quantum dot. Phys Rev B. 44:1646CrossRefGoogle Scholar
  6. Büsser CA, Anda EV, Lima AL, Davidovich MA, Chiappe G (2000) Transport in coupled quantum dots: kondo effect versus anti-ferromagnetic correlation. Phys Rev B. 62:9907CrossRefGoogle Scholar
  7. Chen JC, Chang AM, Melloch MR (2004) Transition between quantum states in a parallel-coupled double quantum dot. Phys Rev Lett 92:176801CrossRefGoogle Scholar
  8. Craig NJ, Taylor JM, Lester EA, Marcus CM, Hanson MP, Gossard AC (2004) Tunable non-local spin control in a coupled quantum dot system. Science 304::565CrossRefGoogle Scholar
  9. Dong B, Lei XL (2002) Kondo effect and anti-ferromagnetic correlation in transport through tunneling-coupled double quantum dots. ibid 65:241304(R)Google Scholar
  10. Georges, Meir Y (1999) Electronic correlations in transport through coupled quantum dots. Phys Rev Lett. 82:3508CrossRefGoogle Scholar
  11. Gómez-Silva G, Avalos-Ovando O. Ladrón de Guevara ML, Orellana PA (2012) Enhancement of thermoelectric efficiency and violation of the Wiedemann-Franz law due to Fano effect. J Appl Phys 111:053704CrossRefGoogle Scholar
  12. Haug H, Jauho AP (2007) Quantum kinetics in transport and optics of semiconductors, 2nd edn. Springer, BerlinGoogle Scholar
  13. Hong XK, Liu YS, Feng JF, Chu JH (2013) Thermal spin current through a double quantum dot molecular junction in the Coulomb blockade regime. J Appl Phys 114:144309CrossRefGoogle Scholar
  14. Izumida W, Sakai O (2000) Two-impurity Kondo effect in double-quantum-dot systems—effect of interdot kinetic exchange coupling. ibid. 62:10260Google Scholar
  15. Jeong H, Chang AM, Melloch MR (2001) The Kondo effect in an artificial quantum dot molecule. Science. 293:2221CrossRefGoogle Scholar
  16. Jiang Z, Sun Q, Wang Y (2005) Kondo transport through serially coupled triple quantum dots. Phys Rev B 72:045332CrossRefGoogle Scholar
  17. Liu YS, Yang XF (2010) Enhancement of thermoelectric efficiency in a double-quantum-dot molecular junction J. Appl Phys 108:023710CrossRefGoogle Scholar
  18. Liu J, Sun Q-F, Xie XC (2010) Enhancement of the thermoelectric figure of merit in a quantum dot due to the Coulomb blockade Effect. Phys Rev B. 81:245323CrossRefGoogle Scholar
  19. Liu YS, Zhang DB, Yang. XF, Feng JF (2011) The role of Coulomb interaction in thermoelectric effects of an Aharonov–Bohm interferometer. Nanotechnology 22:225201CrossRefGoogle Scholar
  20. López R, Aguado R, Platero G (2002) Nonequilibrium transport through double quantum dots: Kondo effect versus antiferromagnetic coupling. Ibid 89:136802CrossRefGoogle Scholar
  21. Sergueev N, Qing-Feng S, Guo H (2002) Spin-polarized transport through a quantum dot: Anderson model with on-site Coulomb repulsion. Phys Rev B 65:165303CrossRefGoogle Scholar
  22. Simon P, López R, Oreg Y (2005) RKKY and magnetic field interactions in coupled Kondo quantum dots. Phys Rev Lett 94:086602CrossRefGoogle Scholar
  23. Torres LEFF, Lewenkopf CH, Pastawski HM (2003) Coherent versus sequential electron tunneling in quantum dots. Phys Rev Lett. 91:116801.CrossRefGoogle Scholar
  24. van der Wiel WG, De Franceschi S, Elzerman JM et al (2002) Electron transport through double quantum dots. Rev Mod Phys. 75:1.CrossRefGoogle Scholar
  25. Vavilov MG, Glazman LI (2005) Transport spectroscopy of Kondo quantum dots coupled by RKKY interaction. Phys Rev Lett 94:086805CrossRefGoogle Scholar
  26. Wang D-K, Sun Q-F, Guo H (2004) Spin-battery and spin-current transport through a quantum dot. Phys Rev B 69:205312CrossRefGoogle Scholar
  27. Yang XF, Liu YS (2013) Pure spin current in a double quantum dot device generated by thermal Bias. J Appl Phys 113:164310CrossRefGoogle Scholar
  28. Yang Z-C, Sun Q-F, Xie XC (2014) Spin-current Seebeck effect in quantum dot systems. J Phys Condens Matter 26:045302CrossRefGoogle Scholar
  29. Zhang GM, Lu R, Liu ZR. And L, Yu (2005) Swapping Kondo resonances in coupled double quantum dots. Phys Rev B 72:073308CrossRefGoogle Scholar
  30. Zianni X (2007) Coulomb oscillations in the electron thermal conductance of a dot in the linear regime. Phys Rev B 75:045344CrossRefGoogle Scholar

Copyright information

© King Abdulaziz City for Science and Technology 2019

Authors and Affiliations

  1. 1.School of Physical Science and TechnologySoochow UniversitySuzhouChina
  2. 2.Department of PhysicsConcordia UniversityMontrealCanada
  3. 3.College of Physics and Electronic EngineeringChangshu Institute of TechnologyChangshuChina

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