Real-Time Observation of Phonon-Mediated σ-π Interband Scattering in MgB2
Real-Time Observation of Phonon-Mediated σ-π Interband Scattering in MgB2
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DOI：
10.1103/physrevlett.119.097002
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发表时间：
2017-08-31
影响因子：
8.6
通讯作者：
Carbone, F.
中科院分区：
文献类型：
--
作者：
Baldini, E.;Mann, A.;Carbone, F.
在具有各向异性电子结构的系统中，例如层状材料石墨、石墨烯和铜酸盐，脉冲光激发可以相干地激发特定的玻色子模式，从而对新兴的电子特性产生奇异的影响。在这里，我们表明，多带超导体MgB（2）中的E-2g声子数量可以通过飞秒激光脉冲选择性增强，从而实现对西格玛电子子系统中载流子数量的瞬态控制。在对 a 轴和 c 轴等离子体频率敏感的光谱区域中跟踪材料光学常数的非平衡演化，并进行理论建模，揭示了 MgB2 中 sigma-pi 带间散射机制的细节。
In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene, and cuprates, impulsive light excitation can coherently stimulate specific bosonicmodes, with exotic consequences for the emergent electronic properties. Here we show that the population of E-2g phonons in the multiband superconductorMgB(2) can be selectively enhanced by femtosecond laser pulses, leading to a transient control of the number of carriers in the sigma-electronic subsystem. The nonequilibrium evolution of the material optical constants is followed in the spectral region sensitive to both the a- and c-axis plasma frequencies andmodeled theoretically, revealing the details of the sigma-pi interband scattering mechanism in MgB2.