A team from Skobeltsyn Institute of Nuclear Physics (MSU) together with their colleagues developed a magnetic waveguide able to sort neutrons with different spins and storethem different layers. The results of the study may help in study of electronic devices based on not charge of electrons but on their quantum state. The article was published in Physical Review B journal.
Waveguides are quite a broad class of objects utilized in many spheres of life, from telecom (optic wave guides) to medicine (a stethoscope is a sound wave guide). The principle of wave guides operation is based on locking a wave between two reflective walls. The same principle of concentration of radiation in a narrow space is used to "lock in" neutrons.
(a) Standard swaveguide structure consisting of reflective layers A and C and transparent layer B between them. (b,c) Magnetic waveguide structure consisting of three layers A, B (magnetic) and C on a substrate D. The red line shows the reflecting ability of the layers. The black line shows depth distribution of neutron density. Spin-up neutrons are trapped into the layer C, and spin-down neutrons into layer B
Credit: Yury Khaydukov
To make a neutron waveguide one needs to place (almost) transparent for neutrons layer between two reflective layers. Created thus neutron well allows to trap neutrons in the central layer (Fig. 1a). Neutron waveguides are also called resonators because the density of neutrons in the transparent layer is amplified resonantly (just like the sound in an empty room). Such resonant amplification may be used in many areas, from fundamental nuclear physics studies to exotic spheres of application (like nano-reactors).
A group of researchers has recently proposedto use as reflecting walls magnetic field rather than substance. The point is that neutrons,like electrons, have their magnetic moment called spin. Due to this magnetic moment neutrons can be reflected from magnetic field, just like light quanta are reflected in the optic fiber.
Moreover, the reflecting ability depends on a neutron's spin: for spin-up particles it is higher than for the spin-down ones. Based on this effect the team has developed a waveguide based on a magnetic reflection. To do this, three layers with similar scattering ability were deposited on a neutron-impenetrable substrate.
The second layer from the top has magnetic moment increasing thusits reflecting ability for spin-up neutrons and reducing it for the spin-down ones. Thus, for different neutrons transparent layers are also different: spin-down particlesare locked in the magnetic layer, and spin-up neutrons - in the non-magnetic one.
"Besides the childish excitement that we've managed to sort and lock neutrons with different spins- we plan to utilize this effect for the research in the field of spintronics, including its new branches as oxide and superconducting," said Dr. Yury Khaydukov, scientific associate of Skobeltsyn Institute of Nuclear Physics (MSU).
Neutron beams for such studies are obtained at research reactors and accelerators. A world class reactor in Russia is e.g. located in Dubna, Moscow Region. A launch of another powerful reactor PIK in Gatchina (Leningrad Region) is scheduled for 2019. This study was conducted at the Munich research reactor in collaboration with scientists from Max Planck Institute for Solid State Research (Germany), Kotelnikov Institute of Radiophysics and Electronics of the Russian Academy of Sciences (Russsia), and Chalmers University of Technology (Sweden).
Yana Khlyustova | EurekAlert!
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Life Sciences
18.07.2018 | Materials Sciences
18.07.2018 | Health and Medicine