Discovery of field-induced pair density wave state in high temperature superconductors

Discovery of field-induced pair density wave state in high temperature superconductors
Superconductors are quantum materials that are perfect transmitters of electricity and electronic information. Presently, cuprates are the best candidate for highest temperature superconductivity at ambient pressure, operating at approximately -120 °C. Improving this involves understanding competing phases, one of which has now been identified. Credit: MPI CPfS, artist credit to K. Fujita, Brookhaven National Lab

Superconductors are quantum materials that are perfect transmitters of electricity and electronic information. Although they form the technological basis of solid-state quantum computing, they are also its key limiting factor because conventional superconductors only work at temperatures near -270 °C. This has motivated a worldwide race to try to discover higher temperature superconductors. Materials containing CuO2 crystal layers (cuprates) are, at present, the best candidate for highest temperature superconductivity, operating at approximately -120 °C. But room temperature superconductivity in these compounds appears to be frustrated by the existence of a competing electronic phase, and focus has recently been on identifying and controlling that mysterious second phase.

Superconductivity occurs when electrons form pairs of opposite spin and opposite momentum, and these "Cooper pairs" condense into a homogeneous electronic fluid. However, theory also allows the possibility that these electron pairs crystallize into a "pair density wave" (PDW) state where the density of pairs modulates periodically in space. Intense theoretical interest has emerged in whether such a PDW is the competing phase in cuprates.

To search for evidence of such a PDW state, a team led by Prof. JC Seamus Davis (University of Oxford) and Prof. Andrew P. Mackenzie (Max Planck Institute CPfS, Dresden) with key collaborators Dr. Stephen D. Edkins and Dr. Mohammad Hamidian (Cornell University) and Dr. Kazuhiro Fujita (Brookhaven National Lab.), used high magnetic fields to suppress the homogeneous in the superconductor Bi2Sr2Ca2CuO2. They then carried out atomic-scale visualization of the electronic structure of the new field-induced phase. Under these circumstances, modulations in the density of electronic states containing multiple signatures of a PDW state were discovered. The phenomena are in detailed agreement with theoretical predictions for a field-induced PDW state, implying that it is a pair density wave which competes with superconductivity in cuprates.

This discovery makes it clear that in order to understand the mechanism behind the enigmatic high temperature superconductivity of the cuprates, this exotic PDW state needs to be taken into account, and therefore opens a new frontier in cuprate research.


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More information: S. D. Edkins et al, Magnetic field–induced pair density wave state in the cuprate vortex halo, Science (2019). DOI: 10.1126/science.aat1773
Journal information: Science

Provided by Max Planck Society
Citation: Discovery of field-induced pair density wave state in high temperature superconductors (2019, June 12) retrieved 22 August 2019 from https://phys.org/news/2019-06-discovery-field-induced-pair-density-state.html
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Jun 12, 2019
What is going on with the two indian scientist that claimed they discovered a way to make room temperature superconductor with gold and silver nanoparticles?
I thought I just read that they republished with better data, more researchers, and it is reproducible.

Jun 12, 2019
I wonder if the pair density wave is a function of Direct Current vs an alternating current scheme. Not sure if that has been checked with superconductivity.

It seems like the density wave function might be able to be mitigated if the correct frequency of an AC like current scheme to keep the density wave function from breaking the conductive state, if the energy can, instead, be transferred and passed along the line without the electron pairs having to move far beyond their initial coupled cuprate atoms then it may be able to stop the spot heating that breaks the line of superconduction.

I know most experiments presently have the current in superconducting use a DC setup, I would like to see if there is a sweet spot in the current frequency that will allow the superconducting Cooper Pairs from gaining heat and thus the disorder that breaks the superconducting state.

Just a thought experiment

Jun 14, 2019
"Superconductivity occurs when electrons form pairs of opposite spin and opposite momentum"

It seems practically like a spin-2 massless particle that could be described by pairs of counter-rotating E-field vector-carriers with the rotating vector pairs distributed over every direction centered around two adjacent counter-rotating points. It's just one more reason to consider quantized gravity carriers as conveying paired counter-rotating field vectors. A realistic view of quantum gravity carrier-particle action there shows how insipid MOND is, comparatively speaking, for explaining dark matter effect peripheral envelopes around individual galaxies.

Of course the dark-matter-reliant supremacist propagandists dominating the ratings show here will have none of it. They'll claim something stupid like propagating effects can't increase over radiated distance.

Jun 14, 2019
Why would there be "two adjacent counter-rotating[sic] points?"

Jun 14, 2019
As one may see, propagandists are fully capable of asking questions that easily appear to come from an over-programmed robot.

Jun 14, 2019
Cranks can't answer the hard questions about their fantasies. It's a sure-fire way of identifying them.

Jun 14, 2019
Say you have a huge number of spinning discs flying out sideways from a single point (as if radiated) in every direction all spinning at the same rate. Suppose no direction of spin or of angle of spin with respect to the horizontal ground is evident. Pretty much half are clockwise-rotating. Of those that are rotating oriented in a horizontal plane, it's still pretty much 50-50 on spin direction. Suppose every disc has an arrow drawn from the center to the edge, and every disc starts out on its radiated path by pointing inward. At the point of ninety-degrees of rotation, all the arrows will point in different directions and net directions pointed thereby will largely cancel out. Dropping one arrow out of the picture does not make a big difference, but pretty much every coplanar-rotating arrow can be paired, clockwise with counterclockwise. Practically the same thing can be approximated with random variables for orientation and spin-direction in there.

Jun 14, 2019
Where do these spinning discs come from?

Unicorn farts?

You should probably have tried to answer the first question instead of proving you're a troll by changing the subject to something ridiculous.

Jun 14, 2019
"Suppose no (bias in) direction of spin or of angle of spin with respect to the horizontal ground is evident." reads better with the part added in parenthesis.

I clarify this stuff DESPITE the insulting jackass questions, not because of them.

Jun 14, 2019
You haven't clarified anything.

Two simple questions:

1. Why would there be "two adjacent counter-rotating[sic] points?"
2, Where do these spinning discs come from?

Either you have answers or you're bullshitting wildly because you're a troll.

Choose one.

Jun 14, 2019
If I was gonna be nasty I'd ask if the spinning disks are the ones the aliens who anal probed you came out from.

Jun 14, 2019
I have to ask, why haven't you guys muted Da Schneib yet?

Jun 14, 2019
I have to ask, why haven't you guys muted Da Schneib yet?


Trolls don't mute anybody or anything including mind reading aliens.

Jun 16, 2019
The disc corresponds to a front-to-back cross-section through a nucleon. Some relevant relations for typical galaxy size and nucleon size:

Force(G) x Distance(G) = Force(E) x Distance(E)

F(Elec_Proton-to-Proton)/F(Grav_Proton-to-Proton) = R(Galaxy)/R(Proton) = 10^+36

10^+36 x R(Nucleon) = R(Galaxy)

A photon comes from single lateral oscillation of an electron around a nucleus.
Spin-2 quantum gravity waves come from the sum of all oscillations of a collection of nucleons.

Jun 16, 2019
Particles aren't little globes.

Sigh.

Jun 16, 2019
My equations above are a form of energy balance. Radii are effective values. ~10^-15m proton is standard.

Both light and gravity can be decomposed into oscillating spin-1 vectors, the idea of gravity vector-pairing for nucleon oscillations is based on large numbers of nucleons oscillating in random planes.

Jun 16, 2019
Errrr, no. Gravity is a spin-2 tensor.

Jun 21, 2019
A vector is a first rank tensor, but the fat douchebag and its legless sock-puppet here know this.

Dirac had a similar idea. He only focused on electron mass/charge force ratio, however, as far as I know.

https://en.wikipe...pothesis

Jun 21, 2019
The writeup on Dirac's LNH is pretty dismal. It's an old idea from the 1930's, and Wikipedia refers to "coincidences" between electrons or between electrons and protons, in terms of electrostatic/gravitational force-ratios, when scaled by a measure of electron radius. There's no realistic concept post-rescaling, instead it is supposed to suggest grandiose things like the size of the universe or the mass of the universe or age of the universe - nothing worthy of being cited as part of a realistic coincidence like an effective size scale for galaxies. Galaxies were known at the time. G is also not a constant for some reason too boring for the wiki writers to try explaining. Maybe G is modulated by a wave, but nobody seems to be saying that anywhere.

Jun 23, 2019
It's a perfect set-up for a sci-fi story nobody ever wrote before: Famous old physicists find out about galaxies and soon afterward write papers on up-scaling charged particles based on proton and electrons in terms of E/G ratios, to find "coincidences" with un-measurable things thereby, while ignoring that proton size times proton-proton E/G force ratio is galactic scale: 10-15 x 10+36 meters = ~100,000 light-years. It makes the patent examiner in my mind take pause.

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