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Quantum valley pseudospin controlled by strain

Maurício F. C. Martins Quintela1,2,3,*, Miguel Sá1,2,3, Alejandro J. Uría-Álvarez3, Mikhail Malakhov4, Giovanni Cistaro1,5, Jorge Quereda6, Juan J. Palacios2,3,7, and Antonio Picón1,2,6,†

  • *Contact author: mfcmquintela@gmail.com
  • †Contact author: antonio.picon@csic.es
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Phys. Rev. Research 7, 043265 – Published 8 December, 2025

DOI: https://doi.org/10.1103/fpwv-vtvk

Abstract

Valleytronics, as an alternative to traditional electronics or spintronics, is based on the encoding of quantum information in pseudospin valley quantum numbers, rather than in charge or spin states. A key ingredient is the (optical) manipulation of valley states before loss of coherence, which can be as fast as 100 fs. Previous works have shown the possibility of valley state manipulation using external fields. Here, we propose uniaxial strain as a more flexible and robust scheme to manipulate the valley state through the breaking of the crystal symmetry and the concomitant lifting of the degeneracy of the 1s exciton energy. Our theory is corroborated by state-of-the-art numerical simulations in monolayer hBN and shows the possibility to control valley pseudospin at the attosecond timescale.

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Phys. Rev. Research 7, 043265– Published 8 December, 2025
  • Received 22 May 2025
  • Revised 10 October 2025
  • Accepted 21 October 2025
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