Modification of the Heavy Hole Wave-function in Multiply Occupied Magnetic Quantum Dots

ORAL

Abstract

We compare the magnetic field PL peak energy red shift of ZnTe Quantum Dots (QDs) embedded in a ZnMnSe matrix using two types of laser excitation: (a) Excitation at 405 nm (3.06 eV) with photon energy above the ZnMnSe matrix gap. This leads to electron-hole pair generation mainly in the matrix. (b) Excitation at 488 nm (2.54 eV) with photon energy below the ZnMnSe matrix gap but above the bandgap of the ZnTe QDs. In the latter case, carriers are excited directly into the ZnTe QDs.
The PL peak energy magnetic red shift is up to 3 times larger with 488 nm excitation compared to excitation using 405 nm excitation. Under 488 nm excitation an additional PL feature associated with the e1l1shell is observed indicating multiple hole occupancy of the QDs. Using exact diagonalization, we study the doubly occupied quantum dot. We find that in our system, the enhanced exchange interaction between the hole and the Mn ion spins causes the triplet state to be the ground state. Furthermore, the hole-hole repulsion results in the extension of the hole wavefunction further into the ZnMnSe matrix which leads to enhanced magnetic PL red shift.

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Presenters

  • James Pientka

    Physics, ST. BONAVENTURE UNIVERSITY, Department of Physics, St. Bonaventure University, St. Bonaventure, NY, St. Bonaventure University

Authors

  • James Pientka

    Physics, ST. BONAVENTURE UNIVERSITY, Department of Physics, St. Bonaventure University, St. Bonaventure, NY, St. Bonaventure University

  • Peiyao Zhang

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Tenzin Norden

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Arman Najafi

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Biplob Barman

    Physics, University of Michigan-Flint, Physics, University of Alabama at Birmingham

  • Yutsung Tsai

    Physics, Univ of Texas

  • Bruce McCombe

    Physics, State Univ of NY - Buffalo, University at Buffalo, The State University of New York

  • Jong E Han

    University at Buffalo, The State University of New York, Department of Physics, State University of New York at Buffalo, Department of Physics, University at Buffalo, Physics, State Univ of NY - Buffalo

  • Igor Zutic

    University at Buffalo, The State University of New York, Department of Physics, State University of New York at Buffalo, Department of Physics, University at Buffalo, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, The State University of New York, Physics, State University of New York at Buffalo

  • Athos Petrou

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Rafal M Oszwaldowski

    Physics, South Dakota School of Mines and Technology

  • Wen-Chung Fan

    National Chiao Tung University

  • Wu-Ching Chou

    National Chiao Tung University