Nav: Home

Which physical mechanism is responsible for magnetic properties of cuprates upon doping?

November 15, 2018

'We study collective electronic effects in various materials, especially in those that are characterized by fairly strong electron-electron interaction,' says Evgeny. 'This interaction leads to such effects as charge ordering, magnetism, superconducting state and others. In this article, we investigated how the properties of cuprates change when impurities are added to the system to reduce the electron concentration in the material. Usually such a process is called hole doping, and the absence of an electron is called a "hole."

It is known that cuprates are antiferromagnets in the normal state. Upon doping the change in the magnetic properties of various cuprates can occur in two scenarios: either antiferromagnetism is destroyed and goes into a canted antiferromagnetic state, or holes begin to form their own magnetic state, which is characterized by a certain wavenumber.

'In the compound that was studied, we witnessed the second scenario, in which antiferromagnetism is stabilized due to strong electron interactions. The holes form their magnetic state, which leaves the antiferromagnetic state unchanged increasing with doping,'explains Evgeny Stepanov. 'What is important is that this process occurs in a wide range of electron concentrations, this allows the antiferromagnetic state to be in resonance at a certain energy. It is still not known for certain which physical mechanism exactly leads to the appearance of superconductivity in these materials. Since we are not the only one studying these materials, there is a theory that it is this resonant antiferromagnetic that is responsible for the superconducting state in cuprates.'

Superconductivity is the property of materials to have zero electrical resistance. In this state, electrons can move freely in this material, transferring an electric charge. Usually, the superconducting state is realized at a sufficiently low temperature of several tens of degrees on the Kelvin scale and/or at high pressure. So, at room temperature, the superconducting state cannot be obtained yet.

From an experimental point of view, cuprates have already been well studied. Theoretically, it is quite difficult to understand what happens in these materials under the action of hole doping and why they exhibit such properties.

'The reason is very strong electron-electron interaction, which does not allow the use of standard theoretical methods for describing electronic properties in such materials,' said the scientist. 'Our task is to use the more advanced methods we developed, try to theoretically explain the presence of a resonant antiferromagnetic state and see what happens to this state upon doping.'

Thus, the results obtained by the authors of the article make it possible to determine which physical mechanism stabilize the resonant antiferromagnetic state, which is possibly responsible for high-temperature superconductivity in cuprates.
The study was carried out by the international group of scientist from Ural Federal University, University of Michigan, Moscow State Universities, Radboud University, Hamburg University and the Russian Quantum Center: Evgeny Stepanov, Lars Peters, Igor Krivenko, Alexander Lichtenstein, Mikhail Katsnelson and Alexey Rubtsov.

Ural Federal University

Related Electron Articles:

Electron caught in the act
Australia's fastest camera has revealed the time it takes for molecules to break apart.
Interaction between the atomic nucleus and the electron on trial
A team of researchers under the leadership of TU Darmstadt and with the participation of scientists from the Physikalisch-Technische Bundesanstalt (PTB) has measured the transition between energy levels of heavy ions with such precision that it has become possible to reassess underlying theories.
Biochar provides high-definition electron pathways in soil
Cornell University scientists have discovered a new high-definition system that allows electrons to travel through soil farther and more efficiently than previously thought.
New electron source for materials analysis
J├╝lich physicists have succeeded in accelerating the determination of material properties as well as making it more efficient.
Controlled electron pulses
The discovery of photoemission, the emission of electrons from a material caused by light striking it, was an important element in the history of physics for the development of quantum mechanics.
New 'electron gun' could help enable X-ray movies
In the journal Optica, researchers at MIT, the German Synchrotron, and the University of Hamburg in Germany describe a new technique for generating electron bursts, which could be the basis of a shoebox-sized device that consumes only a fraction as much power as its predecessors.
Scientists shrink electron gun to matchbox size
In a multi-national effort, an interdisciplinary team of researchers from DESY and the Massachusetts Institute of Technology (MIT) has built a new kind of electron gun that is just about the size of a matchbox.
First multicolor electron microscopy images revealed
The best microscope we have for peering inside of a cell can now produce color images.
Electron scavenging to mimic radiation damage
High energy radiation affects biological tissues, leading to short-term reactions.
Unveiling the electron's motion in a carbon nanocoil
Toyohashi Tech researchers, in cooperation with researchers at University of Yamanashi, National Institute of Technology, Gifu College, and Tokai Carbon Co., Ltd., have? discovered how the electrical resistivity of carbon nanocoils (CNCs) depends on their geometry.

Related Electron Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...