Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover link between magnetic field strength and temperature

21.08.2018

By exploiting properties of quantum spin in crystal vacancies, researchers have attained micron-level resolution in temperature measurement

Researchers recently discovered that the strength of the magnetic field required to elicit a particular quantum mechanical process, such as photoluminescence and the ability to control spin states with electromagnetic (EM) fields, corresponds to the temperature of the material. Based on this finding, scientists can determine a sample's temperature to a resolution of one cubic micron by measuring the field strength at which this effect occurs. Temperature sensing is integral in most industrial, electronic and chemical processes, so greater spatial resolution could benefit commercial and scientific pursuits. The team reports their findings in AIP Advances, from AIP Publishing.


The team created their sensor from a silicon carbide chip synthesized at the Ioffe Physical-Technical Institute.

Credit: Andrey Anisimov

In diamonds, nitrogen atoms can replace carbon atoms; when this occurs next to vacancies in the crystal lattice, it produces useful quantum properties. These vacancies can have a negative or neutral charge. Negatively charged vacancy centers are also photoluminescent and produce a detectable glow when exposed to certain wavelengths of light. Researchers can use a magnetic field to manipulate the spins of the electrons in the vacancies, which alters the intensity of the photoluminescence.

A team of Russian and German researchers created a system that can measure temperatures and magnetic fields at very small resolutions. The scientists produced crystals of silicon carbide with vacancies similar to the nitrogen-vacancy centers in diamonds. Then, they exposed the silicon carbide to infrared laser light in the presence of a constant magnetic field and recorded the resulting photoluminescence.

Stronger magnetic fields make it easier for electrons in these vacancies to transfer between energy spin states. At a specific field strength, the proportion of electrons with spin 3/2 quickly changes, in a process called anticrossing. The brightness of the photoluminescence depends on the proportion of electrons in various spin states, so the researchers could gauge the strength of the magnetic field by monitoring the change in brightness.

Additionally, the luminescence abruptly changes when electrons in these vacancies undergo cross-relaxation, a process where one excited quantum system shares energy with another system in its ground state, bringing both to an intermediate state. The strength of the field needed to induce cross-relaxation is directly tied to the temperature of the material. By varying the strength of the field, and recording when photoluminescence suddenly changed, the scientists could calculate the temperature of the region of the crystal under investigation. The team was surprised to discover that the quantum effects remained even at room temperature.

"This study allows us to create temperature and magnetic field sensors in one device," said Andrey Anisimov, of the Ioffe Physical-Technical Institute of the Russian Academy of Sciences and one of the authors of the paper. Moreover, sensors can be miniaturized to 100 nanometers, which would enable their use in the space industry, geophysical observations and even biological systems. "In contrast to diamond, silicon carbide is already an available semiconductor material, and diodes and transistors are already made from it," Anisimov said.

###

The article, "All-optical quantum thermometry based on spin-level cross-relaxation and multicenter entanglement under ambient conditions in SiC," is authored by Andrey N. Anisimov, Victor A. Soltamov, Ilya D. Breev, Roman A. Babunts, Evgeniy N. Mokhov, Georgy V. Astakhov, Vladimir Dyakonov, Dmitri R. Yakovlev, Dieter Suter and Pavel G. Baranov. The article appeared in AIP Advances August 7, 2018, (DOI: 10.1063/1.5037158) and can be accessed at http://aip.scitation.org/doi/full/10.1063/1.5037158.

ABOUT THE JOURNAL

AIP Advances is an open access journal publishing in all areas of physical sciences--applied, theoretical, and experimental. All published articles are freely available to read, download, and share. The journal prides itself on the belief that all good science is important and relevant. Our inclusive scope and publication standards make it an essential outlet for scientists in the physical sciences. See https://aip.scitation.org/adv/info/focus.

Media Contact

Rhys Leahy
media@aip.org
301-209-3090

 @AIPPhysicsNews

http://www.aip.org 

Rhys Leahy | EurekAlert!

More articles from Physics and Astronomy:

nachricht Matter falling into a black hole at 30 percent of the speed of light
24.09.2018 | Royal Astronomical Society

nachricht Scientists solve the golden puzzle of calaverite
24.09.2018 | Moscow Institute of Physics and Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Matter falling into a black hole at 30 percent of the speed of light

24.09.2018 | Physics and Astronomy

NASA balloon mission captures electric blue clouds

24.09.2018 | Earth Sciences

New way to target advanced breast cancers

24.09.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>