Impact of next-nearest-neighbor hopping on ferromagnetism in diluted magnetic semiconductors
| Autor: | Subrat K. Das, Sourav Chakraborty, Kalpataru Pradhan |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Condensed Matter - Materials Science Strongly Correlated Electrons (cond-mat.str-el) Condensed matter physics Degree (graph theory) Transition temperature Wide-bandgap semiconductor Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology Magnetic semiconductor Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology 01 natural sciences k-nearest neighbors algorithm Condensed Matter - Strongly Correlated Electrons Condensed Matter::Materials Science Delocalized electron Ferromagnetism 0103 physical sciences Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Lattice model (physics) |
| Zdroj: | Physical Review B. 102 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | Being a wide band gap system GaMnN attracted considerable interest after the discovery of highest reported ferromagnetic transition temperature $T_C$ $\sim$ 940 K among all diluted magnetic semiconductors. Later it become a debate due to the observation of either a ferromagnetic state with very low $T_C$ $\sim$ 8 K or sometimes no ferromagnetic state at all. We address these issues by calculating the ferromagnetic window, $T_C$ Vs $p$, within a $t-t'$ Kondo lattice model using a spin-fermion Monte-Carlo method on a simple cubic lattice. We exploit the next-nearest-neighbor hopping $t'$ to tune the degree of delocalization of the free carriers and show that carrier localization (delocalization) significantly widen (shrunken) the ferromagnetic window with a reduction (enhancement) of the optimum $T_C$. We connect our results with the experimental findings and try to understand the ambiguities in ferromagnetism in GaMnN. 10 pages, 7 figures |
| Databáze: | OpenAIRE |
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