Аннотация
Maintaining a population inversion in electron distributions is the first step towards lasing. There is a strong interest in realizing the inversion in a Dirac conical band structure, because broad-band lasing may then be realized owing to the zero-gap nature of the Dirac cone. Here we show that the population inversion can be elongated to >7 ps at 8 K and >10 ps at 300 K on the surface of a p-type topological insulator (Sb0.73Bi0.27)2Te3. Time-and angle-resolved photoemission spectroscopy gives us the direct evidence for the elongated duration of the inversion in the topological surface states. We hereby provide a guideline to prolong the population inversion at finite temperatures. Our study strengthens the route toward the Dirac materials to be a lasing medium.
Язык оригинала | английский |
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Номер статьи | 085302 |
Число страниц | 6 |
Журнал | Physical Review B |
Том | 99 |
Номер выпуска | 8 |
DOI | |
Состояние | Опубликовано - 1 февр. 2019 |