大型非线性光学磁电响应在一个非中心对称的磁性韦尔半金属中
Kentaro Shoriki1, Keigo Moriishi1, Yoshihiro Okamura1
1Department of Applied Physics and Quantum Phase Electronic Center, University of Tokyo, Tokyo 113-8656, Japan.
概括
研究人员在磁性韦尔半金属PrAlGe.Ge中发现了一种大型非线性光学磁电 (ME) 反应. 这种响应是由被打破的反转和时间逆转对称性引起的,使磁场控制的光学属性成为可能.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 拓学材料 拓学材料
背景情况:
- 由于贝里曲率,反转 (P) 或时间逆转 (T) 对称性被打破的韦尔半金属表现出很大的光学反应.
- 光学磁电 (ME) 反应与传统反应不同,在维尔半金属中预测了P和T对称性破坏,提供了多样化的光学功能.
- 在 (半) 金属系统中对光学ME现象的实验观测是有限的.
研究的目的:
- 为了研究一个非中心对称的磁性韦尔半金属中的非线性光学磁电反应.
- 探索破碎的P和T对称度之间的相互作用及其对光学特性的影响.
- 展示这些材料在新型光学功能方面的潜力.
主要方法:
- 非中心对称磁性韦尔半金属 PrAlGe.Ge 的合成和表征.
- 在偏磁和铁磁阶段测量第二波生成 (SHG).
- 研究SHG磁场和光传播方向的依赖性.
主要成果:
- 在PrAlGe中观察到巨大的SHG,与TaAs中的记录值相比,归因于P对称性破坏.
- 由于非磁性和磁性诱导的SHG之间的干扰,铁磁阶段的SHG强度因磁场诱导的切换被证明.
- 发现了显著的非线性光学ME合,其磁性诱导的非线性易感性超过了原型ME材料的易感性.
结论:
- 确定了在P和T对称性被打破的韦尔半对称 PrAlGe.Ge 中存在大量非线性光学ME响应.
- 突出了由于结构不对称性和磁性排序的相互作用而产生的独特光学功能.
- 这些发现为开发具有先进光学应用的新型拓半金属铺平了道路.
相关概念视频
01:26Diamagnetism
2.4K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.4K
01:31Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
01:30Paramagnetism
2.5K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.5K
01:05Atomic Nuclei: Magnetic Resonance
654
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
654
01:31Magnetic Susceptibility and Permeability
1.1K
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
1.1K
01:18Magnetic Field Due to Two Straight Wires
2.5K
Consider two parallel straight wires carrying a current of 10 A and 20 A in the same direction and separated by a distance of 20 cm. Calculate the magnetic field at a point "P2", midway between the wires. Also, evaluate the magnetic field when the direction of the current is reversed in the second wire.
2.5K