Dynamics and Quantum Leakage of InAs/GaAs Double Quantum Dots under Finite Time-Dependent Square-Pulsed Electric Field

Abstract:

We investigate the dynamics and quantum leakage of InAs double quantum dots under the influence of a finite number of square-pulsed electric field whose amplitude varies from −0.3 to 0.3 [mV/A°]. The quantum dots are created to have identical pyramid shape with a square base of length 60.6 [A°] and height 30.3 [A°], and separated by 12.1 [A°]. Such the double quantum dots are proposed as a qubit within the given number of sequent pulses and amplitudes. The investigation consists of two parts: (i) simulations with a tight-binding theory [1] to calculate wavefunctions at constant electric field, and (ii) modeling of a two-level quantum system to calculate the state dynamics on the Bloch sphere [2] using parameters obtained from part (i). Results from part (i) give us wavefunctions under one pulse of constant electric field. After solving equations to match the wavefunctions at each pulse’s boundary, we compute the charge density as a function of times to display the quantum transition from one dot to another. This transition, its probability, and the dynamics on the Bloch sphere can be depicted with the electric field as time increases. For comparison purposes, we find that the dynamics in part (i) does not always lie in the eigenbasis, resulting in the transition probability smaller than that calculated in part (ii). Generally, the probability profiles from both parts are consistent in shape and critical points. For quantum leakage, we obtain a contour plot of the leakage as a function of the number of pulses and amplitudes, which shows that the leakage increases nonlinearly as the number of pulses and amplitude increase. Some pulses seem to induce more leakage than others, depending on the quantum state of the dots when such pulses arrive.

• Periodical: Advanced Materials Research (Volume 1131)
• Pages: 97-105
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1131.97
• Online since: December 2015
• Authors: Aniwat Kesorn, Worasak Sukkabot, Sujin Suwanna*
• Keywords: Double Quantum Dot, Finite Pulse, Quantum Leakage

References

[1] W. Sukkabot, Electronic Structure of Quantum Dot: Tight-Binding Approach, Doctoral Dissertation (2010), Department of Physics, University of Surrey.

[2] T. Fujisawa, T. Hayashi and S. Sasaki, Rep. Prog. Phys. 69, 759-796 (2006).

[3] D. P. DiVincenzo, Topics in Quantum Computers, in Mesoscopic Electron Transport edited L. L. Sohn, L. P. Kouwenhoven, and G. Schon NATO ASI series E 345, Kluwer Academic, Dordrecht, pp.657-677, (1997).

DOI: 10.1007/978-94-015-8839-3_18

[4] T. Hayashi, T. Fujisawa, H. D. Cheong, Y. H. Jeong and Y. Hirayama, Phys. Rev. Lett. 91, 226804 (2003).

[5] J. Gorman, D. G. Hasko, D. A. Williams, Phys. Rev. Lett. 95, 090502 (2005).

[6] T. Fujisawa, T. Hayashi, H. D. Cheong and Y. H. Jeong, Physica E 21, 1046-1052 (2004).

[7] Z. Shi, C. B. Simmons, D. R. Ward, J. R. Prance, R. T. Mohr, T. S. Koh, J. K. Gamble, X. Wu, D. E. Savage, M. G. Lagally, M. Friesen, S. N. Coppersmith, and M. A. Eriksson, Phys. Rev. 88, 075416 (2013).

DOI: 10.1103/physrevb.88.075416

[8] P. Vogl, H. P. Hjalmarson and J. D. Dow, J. Phys. Chem. Solids 44, No. 5, pp.365-378, (1983).

[9] T. Saito, J.N. Schulman and Y. Arakawa, Phys. Rev. B 57, No. 20, 13016, (1998).

[10] R. Santoprete, P. Kratzer, M. Scheffler, R. B. Capaz and B. Koiller, J. Appl. Phys. 102, 023711, (2007).

[11] A. Strozecka, W. Jaskolski, M. Zielinski, G. W. Bryant, Vacuum 74, p.259–262, (2004).

[12] A. V. Nenashev, A. V. Dvurechenskii, A. I. Yakimov and A. F. Zinoveva, Physics of the Solid State 46, 19031942, (2004).

[13] B. Partoens, P. Leoni and F. M. Peeters, Physica E 26, p.312–316, (2005).

[14] W. Sheng and Jean-Pierre Leburton, Phys. Rev. Lett. 88, 167401, (2002).

[15] K. Chang and Jian-Bai Xia, J. Appl. Phys. 84, 1454, (1998).

[16] B. D. Gerardot, W. V. Schoenfeld, I. Shtrichman, C. Metzner and P. M. Petroff, Phys. Rev. B. 65, 081303(R), (2002).

[17] G. Klimeck. Magneto-optical response of InAs lens-shaped self-assembled quantum dots, International Workshop for Computational Electronics, (2003).

[18] T. B. Boykin, G. Klimeck, R. C. Bowen, and F. Oyafuso, Phys. Rev. B 66, 125207 (2002).