Low Carrier Density Metal Realized in Candidate Line-Node Dirac Semimetals CaAgP and CaAgAs
Low Carrier Density Metal Realized in Candidate Line-Node Dirac Semimetals CaAgP and CaAgAs
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DOI：
10.7566/jpsj.85.123701
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发表时间：
2016-11
影响因子：
1.7
通讯作者：
Y. Okamoto;Takumi Inohara;A. Yamakage;Y. Yamakawa;K. Takenaka
中科院分区：
文献类型：
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作者：
Y. Okamoto;Takumi Inohara;A. Yamakage;Y. Yamakawa;K. Takenaka
我们研究多晶样品的六方磷属元素，CaAgP和CaAgAs，这两者都是理想的候选人线节点狄拉克半金属。在本研究中获得的CaAgP和CaAgAs多晶样品是低载流子金属，其中空穴载流子占主导地位。通过结合霍尔系数估计的空穴载流子密度和第一性原理计算计算的电子结构，发现这两个样品都有一个环形环面费米表面，来自一个环形的狄拉克线节点。在磷化物样品中，费米能级EF位于电子带线性色散区的末端附近，而在砷化物样品中，费米能级EF位于该区域的中部，这表明砷化物是一个更有希望揭示线结狄拉克半金属物理的体系.
We study polycrystalline samples of the hexagonal pnictides, CaAgP and CaAgAs, both of which are ideal candidates for line-node Dirac semimetals. The polycrystalline samples of CaAgP and CaAgAs obtained in this study are low-carrier metals, where hole carriers are dominant. By combining the hole carrier densities estimated from Hall coefficients and the electronic structures calculated by first principles calculations, both samples are found to have a ring-torus Fermi surface, derived from a ring-shaped Dirac line node. In the phosphide sample, the Fermi energy EF is located at around the end of the linear dispersion region of the electronic bands, while the EF in the arsenide sample exists in the middle of this region, suggesting that the arsenide is a more promising system for uncovering the physics of line-node Dirac semimetals.