Optical conductivity of Yb1-xLuxB12: Energy gap and mid-infrared peak in diluted Kondo semiconductors
Optical conductivity of Yb1-xLuxB12: Energy gap and mid-infrared peak in diluted Kondo semiconductors
复制标题
Yb1-xLuxB12 的光导率：稀释近藤半导体中的能隙和中红外峰
DOI：
--
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
T. Takabatake
中科院分区：
文献类型：
--
作者：
H. Okamura;M. Matsunami;T. Inaoka;T. Nanba;S. Kimura;F. Iga;S. Hiura;J. Klijn;T. Takabatake
我们测量了Yb1 2 xLu xB12(0<；x<；1)的光学电导S(V)，该体系在x5 0处由近藤半导体演化到x5 1处的非磁性金属。在x5 0处，S(V)显示出明显的能隙，其起始点为~2 0 meV，肩峰位于38 meV。随着x的增加，间隙迅速从底部fi拉入，而肩部保持在；40 mev到x5 12。这些结果表明，Lu掺杂到YBB12中产生了带隙内，但带隙的特征能在很大范围内保持不变。在费米能级附近由Yb4f衍生态产生的特征中红外峰的光谱演化表明，Yb4f电子与传导电子有很强的耦合。
We have measured the optical conductivity s ( v ) of Yb 1 2 x Lu x B 12 (0 < x < 1), where the system evolves from a Kondo semiconductor at x 5 0 to a nonmagnetic metal at x 5 1. For x 5 0, s ( v ) exhibits a clear energy gap with an onset at ; 20 meV and a shoulder at 38 meV. As x increases, the gap is rapidly filled in from the bottom, while the shoulder remains at ; 40 meV up to x 5 12 . These results suggest that Lu substitution into YbB 12 produces an in-gap band, but the characteristic energy for the gap remains unchanged in a wide range of x . Spectral evolutions of a characteristic mid-infrared peak, which results from Yb 4 f -derived states near the Fermi level, suggest a strong coupling of Yb 4 f electrons with conduction electrons.