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arXiv 2001.03027cond-mat.mes-hallphysics.optics
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单量子点中极化子形成过程中的声学声子边带动力学

Acoustic Phonon Sideband Dynamics During Polaron Formation in a Single Quantum Dot

Daniel Wigger, Vage Karakhanyan, Christian Schneider, Martin Kamp, Sven Höfling, Paweł Machnikowski, Tilmann Kuhn, Jacek Kasprzak

摘要:

当电子-空穴对在半导体量子点中被光学激发时,主晶格需要适应所产生的电荷分布的存在。因此,耦合的激子-声子系统必须建立新的平衡,该平衡以称为极化子的准粒子的形式达到。特别地,当激子在比典型晶格动力学更快的时间尺度上突然产生时,晶格位移不能精确地跟随。因此,丰富的动力学的皮秒时间尺度上的耦合系统是预期的。在这项研究中,我们结合模拟和测量的超快,相干,非线性光学响应,获得四波混频光谱,解决这个极化子的形成。通过检测和研究不同温度和不同脉冲延迟下四波混频谱中的声子边带,我们可以得到声子发射和吸收过程的影响,这些过程最终导致波包从量子点中发射出来。

英文摘要:

When an electron-hole pair is optically excited in a semiconductor quantum dot the host crystal lattice needs to adapt to the presence of the generated charge distribution. Therefore the coupled exciton-phonon system has to establish a new equilibrium, which is reached in the form of a quasiparticle called polaron. Especially, when the exciton is abruptly generated on a timescale faster than the typical lattice dynamics, the lattice displacement cannot follow adiabatically. Consequently, a rich dynamics on the picosecond timescale of the coupled system is expected. In this study we combine simulations and measurements of the ultrafast, coherent, nonlinear optical response, obtained by four-wave mixing spectroscopy, to resolve the formation of this polaron. By detecting and investigating the phonon sidebands in the four-wave mixing spectra for varying pulse delays and different temperatures we have access to the influence of phonon emission and absorption processes which finally result in the emission of an acoustic wave packet out from the quantum dot.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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