中国物理B ›› 2026, Vol. 35 ›› Issue (7): 70303-070303.doi: 10.1088/1674-1056/ae1450

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Coherently manipulating triplet-exciton qubit by circularly polarized laser

Longlong Zhang(张龙龙), Hongwei Li(李宏伟), Zhenyu Xu(徐振宇), Mengze Tao(陶孟泽), Rui Chen(陈睿), and Yingqi Ma(马英起)†   

  1. State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2025-06-26 修回日期:2025-10-01 接受日期:2026-10-17 发布日期:2026-07-10
  • 通讯作者: Yingqi Ma E-mail:myq@nssc.ac.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant No. 2022YFF0503603), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB1200200), and the Study Encouragement to Youth Innovation Promotion Association Outstanding Member of the Chinese Academy of Sciences (Grant No. Y2022057).

Coherently manipulating triplet-exciton qubit by circularly polarized laser

Longlong Zhang(张龙龙), Hongwei Li(李宏伟), Zhenyu Xu(徐振宇), Mengze Tao(陶孟泽), Rui Chen(陈睿), and Yingqi Ma(马英起)†   

  1. State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2025-06-26 Revised:2025-10-01 Accepted:2026-10-17 Published:2026-07-10
  • Contact: Yingqi Ma E-mail:myq@nssc.ac.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant No. 2022YFF0503603), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB1200200), and the Study Encouragement to Youth Innovation Promotion Association Outstanding Member of the Chinese Academy of Sciences (Grant No. Y2022057).

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摘要： We theoretically propose a scheme for the coherent manipulation of a single qubit, which is constructed using the self-trapped triplet exciton (STTE) in FM/polymer/FM sandwich. The STTE serves as a quantum dot, comprising two degenerate triplet states with opposite magnetizations, thereby forming the qubit's subspace. We demonstrate that the spin state of this qubit can be coherently manipulated by applying an external circularly polarized laser (CPL) to form the Floquet state. The manipulation exhibits significant helicity dependence: when the CPL's angular momentum is antiparallel to the STTE's spin orientation, the STTE undergoes Rabi oscillations between the $|\uparrow\uparrow\rangle$ and $|\downarrow\downarrow\rangle$ state, corresponding to a $\pi$-rotation around the $x$-axis on the Bloch sphere. Conversely, when the CPL's angular momentum is parallel to the STTE's spin orientation, the STTE remains unresponsive to the CPL. Two-axis coherent control of the STTE qubit can be potentially realized by additionally applying a static magnetic field $B_{z}$. Our work provides a theoretical perspective for realizing the coherent manipulation of a qubit in organic devices.

关键词: triplet exciton, coherent manipulation, qubit, circularly polarized laser

Abstract: We theoretically propose a scheme for the coherent manipulation of a single qubit, which is constructed using the self-trapped triplet exciton (STTE) in FM/polymer/FM sandwich. The STTE serves as a quantum dot, comprising two degenerate triplet states with opposite magnetizations, thereby forming the qubit's subspace. We demonstrate that the spin state of this qubit can be coherently manipulated by applying an external circularly polarized laser (CPL) to form the Floquet state. The manipulation exhibits significant helicity dependence: when the CPL's angular momentum is antiparallel to the STTE's spin orientation, the STTE undergoes Rabi oscillations between the $|\uparrow\uparrow\rangle$ and $|\downarrow\downarrow\rangle$ state, corresponding to a $\pi$-rotation around the $x$-axis on the Bloch sphere. Conversely, when the CPL's angular momentum is parallel to the STTE's spin orientation, the STTE remains unresponsive to the CPL. Two-axis coherent control of the STTE qubit can be potentially realized by additionally applying a static magnetic field $B_{z}$. Our work provides a theoretical perspective for realizing the coherent manipulation of a qubit in organic devices.

Key words: triplet exciton, coherent manipulation, qubit, circularly polarized laser

中图分类号:  (Quantum computation architectures and implementations)

  • 03.67.Lx
85.75.-d (Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields) 71.35.Lk (Collective effects (Bose effects, phase space filling, and excitonic phase transitions))