又一个新物态

[TheMatrix]

[TheMatrix]

2D materials

The current work was guided by recent advances in 2D materials, or those consisting of only one or a few layers of atoms. "The whole world of two-dimensional materials is very interesting because you can stack them and twist them, and sort of play Legos with them to get all sorts of cool sandwich structures with unusual properties," says Paul, first author of the paper.

Those sandwich structures, in turn, are called moiré materials. MIT Physics Professor Pablo Jarillo-Herrero pioneered the field with moiré graphene, which is composed of two sheets of atomically thin layers of graphene placed on top of each other and rotated at a slight angle.

Separately, other scientists have advanced the field of 2D magnets.

What might happen if the two fields—2D magnets and moiré materials—are combined? That is the focus of the current work.

Specifically, the team predicts that a structure made of two layers of a 2D magnet topped by a layer of a 2D semiconductor material will generate a phenomenon called a flat band, in which the electrons in the semiconductor stand still. "That was the theoretically challenging part because it's not a very straightforward thing to ask of an electron. They want to move around. And it takes a lot of fine-tuning to get them to stand still," says Paul.

Getting electrons to be still, however, allows them "to really talk to each other. And that's when all the really interesting things in our field [condensed matter physics] happen," Paul continues.

How does it work?

Key to the research is an exotic particle called a skyrmion that involves a property of electrons called spin (another, more familiar property of electrons is their charge). The spin can be thought of as an elementary magnet, in which the electrons in an atom are like little needles orienting in a certain way. In the magnets on your refrigerator, the spins all point in the same direction.

In a skyrmion, the spins form knot-like whirls that are distributed across the surface of a material. Importantly, skyrmions are topological objects, or those whose properties do not change even when they are subjected to large deformations. (In 2016 the Nobel Prize was awarded to the three scientists who discovered topological phases of matter.) The implication is that future applications of skyrmions would be very robust, or difficult to disrupt, perhaps leading to a better form of computer memory storage.

The MIT team predicts that skyrmions in the 2D magnet layer will "imprint" themselves on the electrons in the semiconductor layer, endowing them with skyrmion-like properties themselves. These properties also stop the movement of the semiconductor's electrons, resulting in the flat band.

[弃婴千枝]

早跟你说了，
这就是陈-simons
广大屁民折腾了几十年3+1维陈-weil理论，
最近几年才发现2+1维不是陈-weil，
应该是陈-simons

所以再过一个世纪，
陈的名号会比82都响亮
你妈，
居然在二战时代就把下一百年的物理一网打尽了

[TheMatrix]

早跟你说了，
这就是陈-simons
广大屁民折腾了几十年3+1维陈-weil理论，
最近几年才发现2+1维不是陈-weil，
应该是陈-simons

所以再过一个世纪，
陈的名号会比82都响亮
你妈，
居然在二战时代就把下一百年的物理一网打尽了

二维确实很有意思。一个是novelty，没见过。另一个是可控，因为我们是三维动物，看二维很可控。

[verdelite]

早跟你说了，
这就是陈-simons
广大屁民折腾了几十年3+1维陈-weil理论，
最近几年才发现2+1维不是陈-weil，
应该是陈-simons

所以再过一个世纪，
陈的名号会比82都响亮
你妈，
居然在二战时代就把下一百年的物理一网打尽了

看把你得瑟的，二战一百周年按照1945算还有22年，按照1939算还有16年，按照1937年算还有14年，按照1931算还有9年，就被你算成一网打尽了。

[弃婴千枝]

你的意思是你的么有量子能在最近这几年粉墨登场？

看把你得瑟的，二战一百周年按照1945算还有22年，按照1939算还有16年，按照1937年算还有14年，按照1931算还有9年，就被你算成一网打尽了。

[萧武达]

是不是符合1970‘s建立的分形方法？

[TheMatrix]

是不是符合1970‘s建立的分形方法？

跟分形没关系。

[萧武达]

跟分形没关系。

是吗？为什么? 分形有没有机会构造跨维度理论/现象？
降维未必可逆，升维呢?
维度变化，（硬要说物理的话），物理规律还一定要一样吗？基本的变量会如何?共形，仿射和射影又会怎么变？
这是很关键的

[Caravel]

这不是搞魔角石墨烯的曹园的老板么？

[verdelite]

你的意思是你的么有量子能在最近这几年粉墨登场？

一切皆有可能。10年有一万个小时的业余时间呢。

[CutPaste]

2D materials

The current work was guided by recent advances in 2D materials, or those consisting of only one or a few layers of atoms. "The whole world of two-dimensional materials is very interesting because you can stack them and twist them, and sort of play Legos with them to get all sorts of cool sandwich structures with unusual properties," says Paul, first author of the paper.

Those sandwich structures, in turn, are called moiré materials. MIT Physics Professor Pablo Jarillo-Herrero pioneered the field with moiré graphene, which is composed of two sheets of atomically thin layers of graphene placed on top of each other and rotated at a slight angle.

Separately, other scientists have advanced the field of 2D magnets.

What might happen if the two fields—2D magnets and moiré materials—are combined? That is the focus of the current work.

Specifically, the team predicts that a structure made of two layers of a 2D magnet topped by a layer of a 2D semiconductor material will generate a phenomenon called a flat band, in which the electrons in the semiconductor stand still. "That was the theoretically challenging part because it's not a very straightforward thing to ask of an electron. They want to move around. And it takes a lot of fine-tuning to get them to stand still," says Paul.

Getting electrons to be still, however, allows them "to really talk to each other. And that's when all the really interesting things in our field [condensed matter physics] happen," Paul continues.

How does it work?

Key to the research is an exotic particle called a skyrmion that involves a property of electrons called spin (another, more familiar property of electrons is their charge). The spin can be thought of as an elementary magnet, in which the electrons in an atom are like little needles orienting in a certain way. In the magnets on your refrigerator, the spins all point in the same direction.

In a skyrmion, the spins form knot-like whirls that are distributed across the surface of a material. Importantly, skyrmions are topological objects, or those whose properties do not change even when they are subjected to large deformations. (In 2016 the Nobel Prize was awarded to the three scientists who discovered topological phases of matter.) The implication is that future applications of skyrmions would be very robust, or difficult to disrupt, perhaps leading to a better form of computer memory storage.

The MIT team predicts that skyrmions in the 2D magnet layer will "imprint" themselves on the electrons in the semiconductor layer, endowing them with skyrmion-like properties themselves. These properties also stop the movement of the semiconductor's electrons, resulting in the flat band.

.

更牛逼，更有趣，更多新发现的，

应是在生命科学领域。且可直接应用。

我自己从业余种植六年多就发现了新成果。



.

[TheMatrix]

是吗？为什么? 分形有没有机会构造跨维度理论/现象？
降维未必可逆，升维呢?
维度变化，（硬要说物理的话），物理规律还一定要一样吗？基本的变量会如何?共形，仿射和射影又会怎么变？
这是很关键的

分形是分数维，这个是二维，严格的理想的二维。

[萧武达]

分形是分数维，这个是二维，严格的理想的二维。

这个有两层意思 1）真实空间，也许就不限定整数维 比如e维更准确的描述； 2）目前的变换映射研究的基本都是同维度的规律和定量， 跨维度还很少见
也许有机会突破一下？（分形几何，有一点有启示-如何从无到有，呵呵呵）

[TheMatrix]

这个有两层意思 1）真实空间，也许就不限定整数维 比如e维更准确的描述； 2）目前的变换映射研究的基本都是同维度的规律和定量， 跨维度还很少见
也许有机会突破一下？（分形几何，有一点有启示-如何从无到有，呵呵呵）

哦那是另一个话题。这里的新物态就是二维。