US-Germany Cooperative Research on Coherence Effects on Nonlinear Optical Properties in Strongly-Correlated Insulators and Metals

该奖项支持加州大学圣地亚哥分校沈璐教授和一名初级研究员与德国耶拿弗里德里希席勒大学的Friedhelm Bechstedt教授合作。 他们正在研究强相关绝缘体和金属中的相干效应。 特别是，他们将研究通过系统的非线性光学响应的相干性的可能的可检测性。 合作的研究小组带来了互补的专业知识，在许多机构的理论和凝聚态系统的光学特性。 强电子-电子关联对现代金属和绝缘体如铜酸盐化合物和重费米子化合物的电子性质起着至关重要的作用。 如果理论上可以证明光激发相干效应的存在，这将为大量金属和绝缘体中的强相关性提供一个可操作的定义。 反过来，这将导致一个光学手段，实验观察强相关行为和一个有效的光学测试的预测强相关理论。

This award supports Professor Lu Sham and a junior associate of the University of California at San Diego to collaborate with Professor Friedhelm Bechstedt of the Friedrich Schiller University of Jena, Germany. They are studying coherence effects in strongly-correlated insulators and metals. In particular, they will investigate the possible detectability of coherence through the nonlinear optical response of the system. The collaborating research groups bring complementary expertise in many body theory and in optical properties of condensed matter systems. Strong electron-electron correlation plays a pivotal role in the electronic properties of modern metals and insulators such as the cuprate compounds and the heavy fermion compounds. If optically excited coherence effects can be shown to exist in theory, this will provide an operational definition for strong correlation in a large number of metals and insulators. In turn, this would lead to an optical means for experimentally observing strongly correlated behavior and an effective optical test for predictions of strong-correlation theories.