- Physical Review Journals
All JournalsPhysics Magazine

Physical Review B

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Letter
  • Open Access

Magnetic tuning of the tunnel coupling in an optically active quantum dot molecule

Frederik Bopp1,*, Charlotte Cullip1,*, Christopher Thalacker1, Michelle Lienhart1, Johannes Schall2, Nikolai Bart3, Friedrich Sbresny4, Katarina Boos4, Sven Rodt2 et al.

Dirk Reuter5, Arne Ludwig3, Andreas D. Wieck3, Stephan Reitzenstein2, Filippo Troiani6, Guido Goldoni6,7, Elisa Molinari6,7, Kai Müller4, and Jonathan J. Finley1,†

  • *These authors contributed equally to this work.
  • †finley@wsi.tum.de
PDF

Phys. Rev. B 112, L060404 – Published 8 August, 2025

DOI: https://doi.org/10.1103/dhjc-fvh3

Abstract

Self-assembled optically active quantum dot molecules (QDMs) allow the creation of protected qubits via singlet-triplet spin states. The qubit energy splitting of these states is defined by the tunnel coupling strength and is, therefore, determined by the potential landscape and is fixed during growth. Applying an in-plane magnetic field increases the confinement of the hybridized wave functions within the quantum dots, leading to a decrease of the tunnel coupling strength. We achieve a tuning of the coupling strength by 53.4%±1.7%. The ability to fine-tune this coupling is essential for quantum network and computing applications that require quantum systems with near identical performance.

View figure in article

Physics Subject Headings (PhySH)

Article Text

Supplemental Material

References (34)

  1. D. A. Lidar, I. L. Chuang, and K. B. Whaley, Decoherence-free subspaces for quantum computation, Phys. Rev. Lett. 81, 2594 (1998).
  2. B. Douçot and L. B. Ioffe, Physical implementation of protected qubits, Rep. Prog. Phys. 75, 072001 (2012).
  3. J. R. Petta, A. C. Johnson, J. M. Taylor, E. A. Laird, A. Yacoby, M. D. Lukin, C. M. Marcus, M. P. Hanson, and A. C. Gossard, Coherent manipulation of coupled electron spins in semiconductor quantum dots, Science 309, 2180 (2005).
  4. M. Stopa and C. M. Marcus, Magnetic field control of exchange and noise immunity in double quantum dots, Nano Lett. 8, 1778 (2008).
  5. K. M. Weiss, J. M. Elzerman, Y. L. Delley, J. Miguel-Sanchez, and A. Imamoğlu, Coherent two-electron spin qubits in an optically active pair of coupled InGaAs quantum dots, Phys. Rev. Lett. 109, 107401 (2012).
  6. K. X. Tran, A. S. Bracker, M. K. Yakes, J. Q. Grim, and S. G. Carter, Enhanced spin coherence of a self-assembled quantum dot molecule at the optimal electrical bias, Phys. Rev. Lett. 129, 027403 (2022).
  7. Y. Benny, S. Khatsevich, Y. Kodriano, E. Poem, R. Presman, D. Galushko, P. M. Petroff, and D. Gershoni, Coherent optical writing and reading of the exciton spin state in single quantum dots, Phys. Rev. Lett. 106, 040504 (2011).
  8. I. Favero, G. Cassabois, R. Ferreira, D. Darson, C. Voisin, J. Tignon, C. Delalande, G. Bastard, Ph. Roussignol, and J. M. Gérard, Acoustic phonon sidebands in the emission line of single InAs/GaAs quantum dots, Phys. Rev. B 68, 233301 (2003).
  9. A. S. Bracker, M. Scheibner, M. F. Doty, E. A. Stinaff, I. V. Ponomarev, J. C. Kim, L. J. Whitman, T. L. Reinecke, and D. Gammon, Engineering electron and hole tunneling with asymmetric InAs quantum dot molecules, Appl. Phys. Lett. 89, 233110 (2006).
  10. F. Martins, F. K. Malinowski, P. D. Nissen, E. Barnes, S. Fallahi, G. C. Gardner, M. J. Manfra, C. M. Marcus, and F. Kuemmeth, Noise suppression using symmetric exchange gates in spin qubits, Phys. Rev. Lett. 116, 116801 (2016).
  11. D. Kim, S. G. Carter, A. Greilich, A. S. Bracker, and D. Gammon, Ultrafast optical control of entanglement between two quantum-dot spins, Nat. Phys. 7, 223 (2011).
  12. H. J. Kimble, The quantum internet, Nature (London) 453, 1023 (2008).
  13. S. E. Economou, N. Lindner, and T. Rudolph, Optically generated 2-dimensional photonic cluster state from coupled quantum dots, Phys. Rev. Lett. 105, 093601 (2010).
  14. R. Raussendorf and H. J. Briegel, A one-way quantum computer, Phys. Rev. Lett. 86, 5188 (2001).
  15. E. Zallo, R. Trotta, V. Kpek, Y. H. Huo, P. Atkinson, F. Ding, T. Ë. Sikola, A. Rastelli, and O. G. Schmidt, Strain-induced active tuning of the coherent tunneling in quantum dot molecules, Phys. Rev. B 89, 241303(R) (2014).
  16. S. G. Carter, A. S. Bracker, M. K. Yakes, M. K. Zalalutdinov, M. Kim, C. S. Kim, B. Lee, and D. Gammon, Tunable coupling of a double quantum dot spin system to a mechanical resonator, Nano Lett. 19, 6166 (2019).
  17. G. Burkard, G. Seelig, and D. Loss, Spin interactions and switching in vertically tunnel-coupled quantum dots, Phys. Rev. B 62, 2581 (2000).
  18. M. Korkusiński and P. Hawrylak, Electronic structure of vertically stacked self-assembled quantum disks, Phys. Rev. B 63, 195311 (2001).
  19. D. Bellucci, F. Troiani, G. Goldoni, and E. Molinari, Neutral and charged electron-hole complexes in artificial molecules: Quantum transitions induced by the in-plane magnetic field, Phys. Rev. B 70, 205332 (2004).
  20. D. Jacob, B. Wunsch, and D. Pfannkuche, Charge localization and isospin blockade in vertical double quantum dots, Phys. Rev. B 70, 081314(R) (2004).
  21. L. G. D. D. Silva, J. M. Villas-Bôas, and S. E. Ulloa, Tunneling and optical control in quantum ring molecules, Phys. Rev. B 76, 155306 (2007).
  22. J. I. Climente, Tuning the tunnel coupling of quantum dot molecules with longitudinal magnetic fields, Appl. Phys. Lett. 93, 223109 (2008).
  23. J. Planelles, J. I. Climente, F. Rajadell, M. F. Doty, A. S. Bracker, and D. Gammon, Effect of strain and variable mass on the formation of antibonding hole ground states in InAs quantum dot molecules, Phys. Rev. B 82, 155307 (2010).
  24. J. Phoenix, M. Korkusinski, D. Dalacu, P. J. Poole, P. Zawadzki, S. Studenikin, R. L. Williams, A. S. Sachrajda, and L. Gaudreau, Magnetic tuning of tunnel coupling between InAsP double quantum dots in InP nanowires, Sci. Rep. 12, 5100 (2022).
  25. H. J. Krenner, M. Sabathil, E. C. Clark, A. Kress, D. Schuh, M. Bichler, G. Abstreiter, and J. J. Finley, Direct observation of controlled coupling in an individual quantum dot molecule, Phys. Rev. Lett. 94, 057402 (2005).
  26. F. Bopp, J. Rojas, N. Revenga, H. Riedl, F. Sbresny, K. Boos, T. Simmet, A. Ahmadi, D. Gershoni, J. Kasprzak et al., Quantum dot molecule devices with optical control of charge status and electronic control of coupling, Adv. Quantum Technol. 5, 2200049 (2022).
  27. P. W. Fry, J. J. Finley, L. R. Wilson, A. Lemaître, D. J. Mowbray, M. S. Skolnick, M. Hopkinson, G. Hill, and J. C. Clark, Electric-field-dependent carrier capture and escape in self-assembled InAs/GaAs quantum dots, Appl. Phys. Lett. 77, 4344 (2000).
  28. See Supplemental Material at http://link.aps.org/supplemental/10.1103/dhjc-fvh3 for further details on the sample structure and theoretical models
  29. M. Bayer, S. N. Walck, T. L. Reinecke, and A. Forchel, Exciton binding energies and diamagnetic shifts in semiconductor quantum wires and quantum dots, Phys. Rev. B 57, 6584 (1998).
  30. M. Bayer, O. Stern, A. Kuther, and A. Forchel, Spectroscopic study of dark excitons in InxGa1−xAs self-assembled quantum dots by a magnetic-field-induced symmetry breaking, Phys. Rev. B 61, 7273 (2000).
  31. M. Bayer, G. Ortner, O. Stern, A. Kuther, A. A. Gorbunov, A. Forchel, P. Hawrylak, S. Fafard, K. Hinzer, T. L. Reinecke, S. N. Walck, J. P. Reithmaier, F. Klopf, and F. Schäfer, Fine structure of neutral and charged excitons in self-assembled In(Ga)As/(Al)GaAs quantum dots, Phys. Rev. B 65, 195315 (2002).
  32. L. Jacak, P. Hawrylak, and A. Wojs, Quantum Dots (Springer Science & Business Media, 2013).
  33. Z. Wasilewski, S. Fafard, and J. McCaffrey, Size and shape engineering of vertically stacked self-assembled quantum dots, J. Cryst. Growth 201–202, 1131 (1999).
  34. R. Colombelli, V. Piazza, A. Badolato, M. Lazzarino, F. Beltram, W. Schoenfeld, and P. Petroff, Conduction-band offset of single InAs monolayers on GaAs, Appl. Phys. Lett. 76, 1146 (2000).

Outline

Information

Phys. Rev. B 112, L060404– Published 8 August, 2025
  • Received 22 March 2023
  • Revised 6 February 2025
  • Accepted 7 July 2025
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation