Thermal and Quantum Melting Phase Diagrams for a Magnetic-Field-Induced Wigner Solid
Thermal and Quantum Melting Phase Diagrams for a Magnetic-Field-Induced Wigner Solid
复制标题
磁场诱导维格纳固体的热熔化和量子熔化相图
DOI：
10.1103/physrevlett.125.036601
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发表时间：
2020
影响因子：
8.6
通讯作者：
Shayegan, M.
中科院分区：
文献类型：
--
作者：
Ma, Meng K.;Villegas Rosales, K. A.;Deng, H.;Chung, Y. J.;Pfeiffer, L. N.;West, K. W.;Baldwin, K. W.;Winkler, R.;Shayegan, M.
足够大的垂直磁场熄灭了相互作用的二维(2D)费米子系统的动能(Fermi)，使它们容易形成Wigner固体(WS)相，在WS相中，带电载流子以周期性阵列组织起来，以最小化它们的库仑排斥能。在低无序的二维电子系统中，调制掺杂的GaAs异质结在低温和极小的朗道能级填充因子()下出现磁场诱导的WS特征。另一方面，在稀薄的GaAs2D空穴系统中，由于空穴有效质量较大以及随后的朗道能级混合，WS形成于相对较高的填充()。在这里，我们测量了2D空穴WS-液体热熔化的基本温度与填充相图。此外，通过改变二维空穴密度，我们还研究了它们的朗道能级混合与填充WS-Liquid量子熔融相图。我们发现我们的数据与最近的计算结果很好地吻合，尽管仍然存在有趣的微妙之处。
A sufficiently large perpendicular magnetic field quenches the kinetic (Fermi) energy of an interacting two-dimensional (2D) system of fermions, making them susceptible to the formation of a Wigner solid (WS) phase in which the charged carriers organize themselves in a periodic array in order to minimize their Coulomb repulsion energy. In low-disorder 2D electron systems confined to modulation-doped GaAs heterostructures, signatures of a magnetic-field-induced WS appear at low temperatures and very small Landau level filling factors (). In dilute GaAs 2D hole systems, on the other hand, thanks to the larger hole effective mass and the ensuing Landau level mixing, the WS forms at relatively higher fillings (). Here we report our measurements of the fundamental temperature vs filling phase diagram for the 2D holes’ WS-liquid thermal melting. Moreover, via changing the 2D hole density, we also probe their Landau level mixing vs filling WS-liquid quantum melting phase diagram. We find our data to be in good agreement with the results of very recent calculations, although intriguing subtleties remain.