I would like to know what is the difference between a Half metal (HM) and a Spin Gapless Semiconductor (SGS) in terms of definition and DOS/Bandstructure appearance.
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1$\begingroup$ Is there any additional context you can provide on your question? Also, you have a different acronym in your title (HSC) than in your question (SGC). Is this a third term you wanted to ask about or an alternative abbreviation of the same concept? $\endgroup$– Tyberius ♦Aug 9, 2021 at 16:19
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$\begingroup$ Concerning the acronym it was just typing a mistake, and about additional context I am familiar with Half-metals but I still don't the know what is Spin Gapless Semi-conductor $\endgroup$– Chi KouAug 10, 2021 at 8:31
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2$\begingroup$ Maybe this article will help, I don't have the time to read through it properly though right now to make a proper answer. aip.scitation.org/doi/10.1063/5.0028918 $\endgroup$– Tristan MaxsonAug 10, 2021 at 18:56
1 Answer
The concept of spin gapless semiconductors (SGS) was proposed in this paper: PRL 100, 156404 (2008).
- In quantum solid-state band theory, materials in nature are generally classified as insulators, semiconductors, metals, semimetals, and half-metals based on the electronic band structures (density of states or band structure), as shown below.
(a): Metal
(b): Semiconductor or Insulator by the gap value
(c): Semimetal (The valence band and conduction band are touching slightly.)
(d): Half-metal
Energy band diagrams for spin gapless semiconductors with linear dispersion between energy and momentum.
- Energy band diagrams for spin gapless semiconductors with parabolic dispersion between energy and momentum.
Compared to the band structure of half metal, one spin channel of SGS is touching slightly (gapless).
Take a careful look at the cited paper and then you will figure out the difference!