Correlation-Enhanced Effective Mass of Two-Dimensional Electrons in MgxZn1-xO/ZnO Heterostructures
Correlation-Enhanced Effective Mass of Two-Dimensional Electrons in MgxZn1-xO/ZnO Heterostructures
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DOI：
10.1103/physrevlett.109.246401
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发表时间：
2012-12-10
影响因子：
8.6
通讯作者：
Iwasa, Y.
中科院分区：
文献类型：
--
作者：
Kasahara, Y.;Oshima, Y.;Iwasa, Y.
我们对限制在MgxZn 1-xO/ZnO异质结构中的二维电子系统进行了结合磁输运和回旋共振实验，载流子密度范围从1.9到12 x 10（11）cm（-2）（3.5小于或类似于r（s）小于或类似于10，其中r（s）是Wigner-Seitz半径）。随着载流子密度的降低，传输质量m（tr）* 强烈增强。与此形成鲜明对比的是，从回旋共振m（CR）* 确定的有效质量被发现是独立的载流子密度和大的体积有效质量。在r（s）类似于10的最低载流子密度处，m（tr）* 的大增强（其超过m（CR）* 类似于60%）完全归因于强电子相关。
We performed combined magnetotransport and cyclotron resonance experiments on two-dimensional electron systems confined in the MgxZn1-xO/ZnO heterostructures over a wide range of carrier densities, from 1.9 to 12 x 10(11) cm(-2) (3.5 less than or similar to r(s) less than or similar to 10, where r(s) is the Wigner-Seitz radius). As the carrier density was reduced, the transport mass m(tr)* was strongly enhanced. In marked contrast, the effective masses determined from the cyclotron resonance m(CR)* were found to be independent of the carrier density and as large as the bulk effective mass. The large enhancement of m(tr)*, which exceeds m(CR)* by similar to 60%, at the lowest carrier density with r(s) similar to 10 is purely attributed to the strong electron correlation.