Thermoelectric response in the incoherent transport region near Mott transition: The case study of La1−xSrxVO3
Thermoelectric response in the incoherent transport region near Mott transition: The case study of La1−xSrxVO3
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DOI：
10.1103/physrevb.83.165127
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发表时间：
2011-03
影响因子：
3.7
通讯作者：
M. Uchida;K. Oishi;M. Matsuo;W. Koshibae;Y. Onose;M. Mori;J. Fujioka;S. Miyasaka;S. Maekawa;Y. Tokura
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文献类型：
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作者：
M. Uchida;K. Oishi;M. Matsuo;W. Koshibae;Y. Onose;M. Mori;J. Fujioka;S. Miyasaka;S. Maekawa;Y. Tokura
本文系统地研究了一种典型的填充控制Mott转变系统La1-xSrxVO3的高温热电响应。在Mott相变附近，随着温度的升高，非相干电荷输运出现，热电势经历了两个本质的交叉，渐近接近由熵考虑所期望的极限值，即海克斯公式。通过与动力学平均场理论的结果比较，我们发现在Mott临界态下的热电势主要测量每个电荷载流子的熵，这取决于在测量温度下可用的电子自由度。我们的发现证实了海克斯公式确实适用于实际温度下(T>；200K)的真实关联电子系统。
We report a systematic investigation on the high-temperature thermoelectric response in a typical filling-control Mott transition system La1-xSrxVO3. In the vicinity of the Mott transition, incoherent charge transport appears with increasing temperature and the thermopower undergoes two essential crossovers, asymptotically approaching the limit values expected from the entropy consideration, as known as Heikes formula. By comparison with the results of the dynamical mean field theory, we show that the thermopower in the Mott critical state mainly measures the entropy per charge carrier that depends on electronic degrees of freedom available at the measurement temperature. Our findings verify that the Heikes formula is indeed applicable to the real correlated electron systems at practical temperatures (T>200K).