Tiedian distant relatives are superconducting neighbors

At the time of middle school, students are estimated that the teacher will give them popular science "what is superconductivity." The general physical speech is to meet the two characteristics of "superconductivity": (1) zero resistance; (2) anti -magnetic or Masner effect. Readers who do not learn physics or ordinary people may really deal with superconducting electrical transactions in eight lives. At this time, the superconductivity in their minds is degenerating zero resistance, which may not be said to be the difference between the limit and zero resistance. As for whether the Masna effect exists, it was slowly forgotten.

What is the problem that the physics is unhappy is how such a problem can be forgotten: the Masner effect is the first priority of superconducting.

In such a general trend, the connection between superconductivity and insulators is like the Haoyue Xinghe, which will not appear in our daily scientific research life. The accumulation of physical knowledge in the past also tells us that superconductors are metals and alloys with good conductivity. Until the high temperature superconducting appears, it allows us to "wake up at the beginning of dreams": The mother of the copper -based superconductor is an anti -iron magnet MOTT insulator. It is doped with some cave carriers, and it calls zero resistance. In the coordinate plane composed of copper oxides, the zero-resistant area presents a dome shape, which becomes a superconductucting dome. This superconducting dome has some romantic connections with the Haoyue Xinghe of the Sky, although the superconducting dome has always been a low Mongolian bag and rarely stands through the clouds.

As a result, the quantum material people began to open their brains, and they understood that superconducting electrical can be born from "any" material, from metal to semiconductor to insulators, from block to interface to two -dimensional materials, from mediocre topology to topology non -topology Merid, you can be super -guided. Therefore, if quantum materials are coldly revealing a new superconducting phenomenon from a field of superconductive electrical, it is the normal state today, although many physics, including the editor, are sincere and panicked. Essence

Figure 1. The phase map of the iron electric superconductor, the superconducting dome appears near the anti -iron electrical QCP.

https://www.phy.cam.ac.uk/research/research-groups/qm/ferroelectrics

For example, the editor never thought that the iron electrical body that was neither magnetic and extreme insulation would really be superconducting, although occasionally in the field of academic discussions in the field, such jokes. However, to this day, the far -reaching, starship of the Xinghe River is really a flavor, as shown in Figure 1. May wish to start with superconductivity from the iron electrical body, and pump the cocoon:

(1) One of the elements: carrier. Since it is necessary to move towards zero resistance, it is inevitable that the carrier doping is necessary to make the carrier reaches a certain concentration to facilitate the formation of a sufficient coqual pair required for macroexgly condensation. However, this doping cannot be excessive, avoiding completely shielding iron electrode, so that the basic characteristics of iron electrical symmetry are lost. In this sense, this is the "helplessness" often faced in physics. This feature is the most vivid in SRTIO3 (STO): with the help of NB5+ions to introduce carrier, the doping amount is about 0.05% ~ 0.5%, which is a trace level. At this time, the experiment did observe the superconductivity, and at the same time maintained the polarization of the micro area.

(2) Elementary two: At least the BCS theory said that the basic element of superconducting is the appropriate sound of the vocal model, and this sound -mocolmore mode must be able to implicate a pair of electrons to form a self -rotating single -state coquet. From the perspective of BCS theory, such sound -like models are best to have longitudinal optical mold LO, and it seems that the more pure sound is the better. Unfortunately, the softening of the sound of the iron electrode must be the horizontal optical mold (to). Therefore, people who are familiar with BCS are also too lazy to connect the iron electrical sound with Cooper. Although the TO model must not be involved in a pair of electrons, at least the intensity is the same.

(3) Quantum critical point QCP: This is a fixed association formed after the discovery of high temperature superconductors. Including copper -based and iron -based superconductors, and even touches topological superconductors, as long as QCP exists in the superconducting phase diagram, such as CDW, 赝 energy gaps, abnormal metals, QCP induced by the associated Feimi liquid state, etc. The dome is no longer nonsense. Interestingly, the theory of soft models of iron electrode is also the theory of implication of the sound of the soundtrack and the puppet. In this sense, the physics person has split iron electrical physics and superconducting electrical ends in the early years. It seems a bit ideal and high. Such a physics person mainly refers to ordinary people who are not exquisite and stubborn. But this is not the case of the great god Anderson. He is not only a superconductant physics, but also the proposal of the iron and electric soft model mechanism.

Figure 2. The dependency of the muddy BATIO3 neutron dynamics and the crystal structure and the load (electron) concentration n. (A) Three ZONE-CENTER POLAR OPTICAL Phonons. (B) N-dependent sound spectrum, softened at N ~ 0.10, this is the critical point of iron and electricity changes. T is a square phase and C is a cubic phase. (C) The relationship between electrical-sound-coupled coupling coefficient and n. (D) The relationship between TC and N critical superconducting temperature. Obviously, n ~ 0.10 is the QCP, and the superconducting dome may appear. From Chen Hanghui research group, J. Ma Et Al, NC 12, 2314 (2021), https://www.nature.com/articleS/S41467-021-22541-1

(4) Mutual exclusion of iron and superconducting: This may be an inherent incompetent harmony. The polarization of the iron electrical body corresponds to the freezing of the single -sound mold (the end point of the so -called sound -mode softening), and finally moves to silence. However, the induced Curdine-sound-vocal coupling of the cooper is Dynamic, which is rejected with the iron electrocomputer requirements. This image is very similar to the mutual relief of electromagnetic effects. Magnetic actually comes from the motion of charge, which is the relativity effect; and the iron electrical is derived from the static electric puppet, and the two cannot be compatible. Therefore, at the same time, at a certain temperature, it is not possible to serve both the electric-vocal coupling to generate the cooper pair and serve the long-term electric long program. Of course, superconductivity is achieved in the iron electrical state that has been formed. If different sounds are used, there will be theoretical possibilities. This also explains why superconductivity is mainly observed in the quantum custard: In these systems, the electric puppets associated with iron electric soft models are in the height rise before frozen. If the corresponding sound of the sound is the need for the formation, the superconductive electrical appearance will be physically logically.

(5) Iron Electric Metal: When Anderson proposed the concept of iron and electric metal in the 1960s, it may only be based on a symmetrical expansion. However, if the system can be pushed near the QCP of the iron power metal state, it may be the state that is closest to superconductivity.

(6) The uniqueness of STO: As the most typical quantum smooth body, STO is also a good film substrate. In the research on iron-based superconducting, a single layer FESE deposited on the STO substrate can show strong electric-sound-vocal coupling and high superconducting temperature. This result was attributed to the STO substrate to provide an unusual sound mode, which significantly enhanced the electrical-vocal coupling coefficient. The physics who is familiar with the BCS theory immediately understands the truth. It is also worth adding here: STO is a strong anti -magnetic compound!

The editor believes that with the above six small points, there may be more. It is inevitable that quantum materials people have a strong interest in iron electricity superconducting. Please note that the editor is just a man -gun here. The sorting of these knowledge has long been seen in literature and books. Many well -known scholars, including the field of quantum materials, have also had a soft spot for this topic. In China, teams committed to this direction include West Lake University, Tsinghua University, New York University (Shanghai), Nanjing University, Southeast University and other institutions. Internationally, the quantum material team participating in this direction is more than domestic, especially for so many years of teams that have been committed to quantum smooth electricity and oxide two -dimensional electronic physics research. They all have good work. As shown in Figure 2, Professor Chen Hanghui of New York University (Shanghai) recently shows this spirit.

Recently, Professor S. Raghu, the theoretical condensation of Stanford University, and Professor Harold Y. HWANG, a master of Stanford's colleagues, a master of transitional metal oxide physics, and Professor SUK BUNG, Seoul University, South Korea, published in "NPJ QM" in "NPJ QM". A paper is dedicated to developing superconductive electrical theory in quantum smooth electrical bodies.

Figure 3. The physical sign of the horizontal sound model TO1 and electronic coupling in the STO of the Raghu research group (upper). Calculated the relationship between the electrical -vocal coupling coefficient and the carrier concentration n (lower).

Readers who are familiar with quantum materials should know that Harold HWANG is actually an experimental scholar, but he has a deep physics accomplishment in quantum smoothness, STO, and his heterogeneous knots. The subcourse mechanism has unique insights. Therefore, he participated in and could contribute to the theory of development. In fact, if readers read this article, they can find that the development of this theory is full of the wisdom and visibility of the experiments, including the physical details of the carrier concentration, the soundtrack spectrum, and the single -loud subsidy. A theoretical article, with this trait, can also be regarded as an innovative model of the theoretical and experimental physics.

The prediction of this theoretical work is directly and concise: In the quantum smoothing STO, the superconductivity caused by the mixing of the load, and its counterattack is derived from a single horizontal optical vocal model that is softened! Figure 3 shows the result of their prediction. It seems that the horizontal son -in -law to form an important physical element for the formation of Cooper. The more pure and better. The freezing of this model is the form of iron electrode.

We all know that the more concise the conclusion, the higher the degree of the autumn water articles! This is forcing Ising to dare not write it again! The ending of Lei can't move: The editor is a layman. If you understand it wrong, please forgive me. If you are interested, please go to the original text of Yulan. The original link information is as follows:

Theory of superconductivity in dopeed quantum ParaElectrics

Yue yu, Harold Y. Hwang, S. Ragu Suk Bum Chung

npj Quantum Materials Volume 7, Article Number: 63 (2022)

Seven Law · Iron Electric also quantum

Yesterday, Luyang Liangzifang, I have to be iron -oriented

Yagong breaks the lack of waves, and can bring to fill the Belly makeup

Brother Fuck? Electrocoupled coupling method

Whoever speaks is a lonely cold, and the story of the book is Weiyang

Remark:

(1) Editor Ising, served as the School of Physics, Nanjing University, and edited part -time "NPJ Quantum Materials".

(2) The titled "Iron Electricity is a superconducting close neighbor" exaggerated expresses the iron electrical and superconductive electricality, but it is still close.

(3) The picture of the text is taken in Hefei Emerald Lake, showing the distance and impression (20200920). Small words were originally written during the Fund Committee-the Chinese Academy of Sciences' Quantum Material and Application Strategy Symposium (20200920).

(4) The cover picture shows the iron and electronic sound model at the FESE -SRTIO3 interface, from the research group of Wang Qianghua, Nanjing University, https://arxiv.org/abs/1202.4141.

Reprinted content only represents the author's point of view

Does not represent the position of the Institute of Physics of the Chinese Academy of Sciences

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Source: Quantum Materials

Edit: Lezi Superman

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