在一个未补偿的反铁磁体MnBi2Te4中,内在交换偏差异化的异常霍尔效应
Su Kong Chong1, Yang Cheng2, Huiyuan Man3,4
1Department of Electrical and Computer Engineering, University of California, Los Angeles, CA, 90095, USA. sukongc@g.ucla.edu.
Nature communications
|April 3, 2024
概括
研究人员开发了一种新方法来稳定拓反铁磁体中的磁相互作用. 这种技术在MnBi2Te4中实现了强大的,可调节的交换偏差,为先进的自旋电子设备铺平了道路.
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
- 这就是Spintronics.
背景情况:
- 铁磁/反铁磁异构结构中的常规交换偏差面临由于接口质量和旋困难的挑战.
- 控制接口属性对于旋转器件中稳定的磁相互作用至关重要.
- 现有的方法通常需要复杂的制造,并且对接口缺陷敏感.
研究的目的:
- 提出和演示一种替代方法来稳定在不补偿的反铁磁铁的界面上的交换相互作用.
- 为了利用层间交换合的梯度来实现可调节的交换偏差.
- 探索拓反铁磁体在旋转子应用中的潜力.
主要方法:
- 为奇数层拓反铁磁体MnBi2Te4.4设计了一个现场训练协议.
- 通过控制的磁场应用研究了交换相互作用.
- 分析了由此产生的交换偏差属性,包括大小,可重复性和重置行为.
主要成果:
- 在MnBi2Te4.4中达到高达400mT的显著现场训练的交换偏差.
- 使用训练场证明了高可重复性和易于重置的交换偏差.
- 观察到现场训练的交换偏差的持久性,即使是零场初始化,与传统方法形成鲜明对比.
结论:
- 拟议的方法有效地稳定了单个抗铁磁化合物中的交换相互作用,从而消除了对额外磁层的需求.
- 这种高度可调和和持久的现场训练的交换偏差为自旋电子设备设计提供了一条新的途径.
- 这些发现为交换相互作用机制提供了关键的见解,并使拓反铁磁旋转电子系统的系统设计成为可能.
相关概念视频
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
01:26Diamagnetism
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
01:30The Hall Effect
2.4K
Edwin H. Hall, in the year 1879, devised an experiment that could be used to identify the polarity of the predominant charge carriers in a conducting material. From a historical perspective, this experiment was the first to demonstrate that the charge carriers in most metals are negative.
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
03:02Colors and Magnetism
11.7K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.7K
00:59Atomic Nuclei: Nuclear Magnetic Moment
1.1K
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, these nuclei generate a magnetic field (B). This, in turn, gives rise to a magnetic moment (μ), which is randomly oriented in the absence of an external magnetic field. When an external magnetic field (B0) is applied, the magnetic moment vectors can align with the field or against it in 2 + 1 orientations. A hydrogen nucleus, which is just a...
1.1K