Directional ballistic transport in the two-dimensional metal PdCoO(2).
Directional ballistic transport in the two-dimensional metal PdCoO(2).
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DOI：
10.1038/s41567-022-01570-7
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发表时间：
2022
期刊：
影响因子：
19.6
通讯作者：
中科院分区：
文献类型：
--
作者：
在理想化的无限晶体中，材料性质受到晶胞对称性的约束。任何有限晶体的样品形状都会破坏点群对称性，但这在宏观金属中通常无法观察到。为了检测这种金属中形状诱导的对称性降低，需要来自各向异性费米表面的长寿命体态。在这里，我们展示了如何一个强刻面费米表面和长准粒子平均自由程存在于PdCoO2的微观结构产生一个平面内的电阻率各向异性，是禁止的对称性上的无限六边形晶格。我们制造条形运输设备窄于平均自由程从单晶使用聚焦离子束铣削，这样的弹道电荷载流子在低温下经常与限定通道的两个侧壁碰撞。出现了两个禁戒输运特征：面内电阻率各向异性超过2倍，零磁场下出现横向电压。使用弹道蒙特卡罗模拟和玻尔兹曼方程的数值解，我们确定的方向的窄通道的对称性破缺的来源。PdCoO2中的电子在被散射之前可以走很长的路，并且它们的能带结构使得它们只能在三个方向中的一个方向上行进。因此，通过这种纳米级导体的电流可以非常有效。
In an idealized infinite crystal, the material properties are constrained by the symmetries of the unit cell. The point-group symmetry is broken by the sample shape of any finite crystal, but this is commonly unobservable in macroscopic metals. To sense the shape-induced symmetry lowering in such metals, long-lived bulk states originating from an anisotropic Fermi surface are needed. Here we show how a strongly facetted Fermi surface and the long quasiparticle mean free path present in microstructures of PdCoO2 yield an in-plane resistivity anisotropy that is forbidden by symmetry on an infinite hexagonal lattice. We fabricate bar-shaped transport devices narrower than the mean free path from single crystals using focused ion beam milling, such that the ballistic charge carriers at low temperatures frequently collide with both of the side walls that define the channel. Two symmetry-forbidden transport signatures appear: the in-plane resistivity anisotropy exceeds a factor of 2, and a transverse voltage appears in zero magnetic field. Using ballistic Monte Carlo simulations and a numerical solution of the Boltzmann equation, we identify the orientation of the narrow channel as the source of symmetry breaking. Electrons in PdCoO2 can travel a long way before being scattered, and their band structure is such that they can travel in only one of three directions. As a result, the current flow through this nanoscale conductor can be very efficient.
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影响因子：
16.6
作者：
Gooth J;Menges F;Kumar N;Süβ V;Shekhar C;Sun Y;Drechsler U;Zierold R;Felser C;Gotsmann B
通讯作者：
Gotsmann B
影响因子：
8.6
作者：
KRISHANA, K;HARRIS, JM;ONG, NP
通讯作者：
ONG, NP
DOI：
10.1017/s0305004100019952
发表时间：
1938-01-01
影响因子：
--
作者：
Fuchs, K
通讯作者：
Fuchs, K
DOI：
10.1088/0370-1301/69/4/304
发表时间：
1956-01-01
期刊：
PROCEEDINGS OF THE PHYSICAL SOCIETY OF LONDON SECTION B
影响因子：
--
作者：
ENGLMAN, R;SONDHEIMER, EH
通讯作者：
SONDHEIMER, EH
影响因子：
5.7
作者：
Nandi, Nabhanila;Scaffidi, Thomas;Mackenzie, Andrew P.
通讯作者：
Mackenzie, Andrew P.