2017/03/01 by Yanhao Tang, Tang, Yanhao, Mersedeh Saniepay +7 · 1 citation
Physics and Astronomy · #Semiconductor Quantum Structures and Devices #Spectroscopy and Quantum Chemical Studies #Laser-Matter Interactions and Applications
paper · pdf · doi:10.48550/arxiv.1703.00530
The k⋅ p effective mass approximation (EMA) predicts large, nearly size-independent exciton oscillator strengths in quantum confined semiconductors. Yet, experimental reports have concluded that the total oscillator strength of the lowest-energy (1S3/21Se) excitons in strongly confined CdSe NQDs is small and strongly size-dependent. Using the optical Stark effect, we show that the oscillator strength of the 1S3/21Se excitonic absorption peak in CdSe NQDs follows the predictions of the EMA. These oscillator strengths enable helicity-selective unsaturated Stark shifts corresponding to femtosecond pseudo-magnetic fields exceeding 100 T.