Abstract
Magnetic doping of semiconductor nanostructures is actively pursued for applications in magnetic memory and spin-based electronics. Central to these efforts is a drive to control the interaction strength between carriers (electrons and holes) and the embedded magnetic atoms. In this respect, colloidal nanocrystal heterostructures provide great flexibility through growth-controlled 'engineering' of electron and hole wavefunctions in individual nanocrystals. Here, we demonstrate a widely tunable magnetic sp-d exchange interaction between electron-hole excitations (excitons) and paramagnetic manganese ions using 'inverted' core-shell nanocrystals composed of Mn 2+ -doped ZnSe cores overcoated with undoped shells of narrower-gap CdSe. Magnetic circular dichroism studies reveal giant Zeeman spin splittings of the band-edge exciton that, surprisingly, are tunable in both magnitude and sign. Effective exciton g-factors are controllably tuned from '200 to +30 solely by increasing the CdSe shell thickness, demonstrating that strong quantum confinement and wavefunction engineering in heterostructured nanocrystal materials can be used to manipulate carrier-Mn 2+ wavefunction overlap and the sp-d exchange parameters themselves.
| Original language | English |
|---|---|
| Pages (from-to) | 35-40 |
| Number of pages | 6 |
| Journal | Nature Materials |
| Volume | 8 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 2009 |
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ASJC Scopus subject areas
- Mechanical Engineering
- Mechanics of Materials
- Condensed Matter Physics
- Materials Science(all)
- Chemistry(all)
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Tunable magnetic exchange interactions in manganese-doped inverted core-shell ZnSe-CdSe nanocrystals. / Bussian, David A.; Crooker, Scott A.; Yin, Ming; Brynda, Marcin; Efros, Alexander L.; Klimov, Victor I.
In: Nature Materials, Vol. 8, No. 1, 01.2009, p. 35-40.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Tunable magnetic exchange interactions in manganese-doped inverted core-shell ZnSe-CdSe nanocrystals
AU - Bussian, David A.
AU - Crooker, Scott A.
AU - Yin, Ming
AU - Brynda, Marcin
AU - Efros, Alexander L.
AU - Klimov, Victor I
PY - 2009/1
Y1 - 2009/1
N2 - Magnetic doping of semiconductor nanostructures is actively pursued for applications in magnetic memory and spin-based electronics. Central to these efforts is a drive to control the interaction strength between carriers (electrons and holes) and the embedded magnetic atoms. In this respect, colloidal nanocrystal heterostructures provide great flexibility through growth-controlled 'engineering' of electron and hole wavefunctions in individual nanocrystals. Here, we demonstrate a widely tunable magnetic sp-d exchange interaction between electron-hole excitations (excitons) and paramagnetic manganese ions using 'inverted' core-shell nanocrystals composed of Mn 2+ -doped ZnSe cores overcoated with undoped shells of narrower-gap CdSe. Magnetic circular dichroism studies reveal giant Zeeman spin splittings of the band-edge exciton that, surprisingly, are tunable in both magnitude and sign. Effective exciton g-factors are controllably tuned from '200 to +30 solely by increasing the CdSe shell thickness, demonstrating that strong quantum confinement and wavefunction engineering in heterostructured nanocrystal materials can be used to manipulate carrier-Mn 2+ wavefunction overlap and the sp-d exchange parameters themselves.
AB - Magnetic doping of semiconductor nanostructures is actively pursued for applications in magnetic memory and spin-based electronics. Central to these efforts is a drive to control the interaction strength between carriers (electrons and holes) and the embedded magnetic atoms. In this respect, colloidal nanocrystal heterostructures provide great flexibility through growth-controlled 'engineering' of electron and hole wavefunctions in individual nanocrystals. Here, we demonstrate a widely tunable magnetic sp-d exchange interaction between electron-hole excitations (excitons) and paramagnetic manganese ions using 'inverted' core-shell nanocrystals composed of Mn 2+ -doped ZnSe cores overcoated with undoped shells of narrower-gap CdSe. Magnetic circular dichroism studies reveal giant Zeeman spin splittings of the band-edge exciton that, surprisingly, are tunable in both magnitude and sign. Effective exciton g-factors are controllably tuned from '200 to +30 solely by increasing the CdSe shell thickness, demonstrating that strong quantum confinement and wavefunction engineering in heterostructured nanocrystal materials can be used to manipulate carrier-Mn 2+ wavefunction overlap and the sp-d exchange parameters themselves.
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U2 - 10.1038/nmat2342
DO - 10.1038/nmat2342
M3 - Article
C2 - 19079242
AN - SCOPUS:57849092617
VL - 8
SP - 35
EP - 40
JO - Nature Materials
JF - Nature Materials
SN - 1476-1122
IS - 1
ER -