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arXiv 1612.04072cond-mat.quant-gascond-mat.mes-hall
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光生偶极激子和自由空穴束缚系综中的集体电子激发

Collective electronic excitation in a trapped ensemble of photogenerated dipolar excitons and free holes revealed by inelastic light scattering

Sebastian Dietl, Sheng Wang, Dieter Schuh, Werner Wegscheider, Jörg P. Kotthaus, Aron Pinczuk, Alexander W. Holleitner, Ursula Wurstbauer

摘要:

光生激子系综限制在耦合GaAs量子阱探测发射光谱和共振非弹性光散射的互补方法。横向静电陷阱的几何形状被用来创建空间间接激子和多余的空穴具有类似的密度在10 $^{11}$ cm $^{-2}$的顺序的密集系统。非弹性光散射光谱揭示了一个非常尖锐的低洼集体模式,确定在0.44 meV的能量和半高宽只有~50 $μ$ eV。这种模式被解释为耦合到光生间接激子的过量空穴系统的等离子体激元激发。间接激子的发射能量在垂直施加的电场的应用下移动,其中量子限制斯塔克效应不受自由载流子的存在的干扰。我们的结果说明了研究光生激子系统中的低位集体激发的潜力,以探索多体相图,相关的相变,和相互作用物理。

英文摘要:

Photogenerated excitonic ensembles confined in coupled GaAs quantum wells are probed by a complementary approach of emission spectroscopy and resonant inelastic light scattering. Lateral electrostatic trap geometries are used to create dense systems of spatially indirect excitons and excess holes with similar densities in the order of 10$^{11}$ cm$^{-2}$. Inelastic light scattering spectra reveal a very sharp low-lying collective mode that is identified at an energy of 0.44 meV and a FWHM of only ~50 $μ$eV. This mode is interpreted as a plasmon excitation of the excess hole system coupled to the photogenerated indirect excitons. The emission energy of the indirect excitons shifts under the application of a perpendicular applied electric field with the quantum-confined Stark effect unperturbed from the presence of free charge carriers. Our results illustrate the potential of studying low-lying collective excitations in photogenerated exciton systems to explore the many-body phase diagram, related phase transitions, and interaction physics.

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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