Direct observation of the transition from spin waves to the magnon Bose condensate.

Bose-Einstein condensation occurs at an appropriate density of bosonic particles, depending on their mass and temperature. The transition from the semiclassical paradigm of spin waves to the magnon Bose-Einstein condensed state (mBEC) was obtained experimentally with increasing magnon density. We used the Faraday rotation effect to study the spatial distribution of the magnon density and phase far from their excitation region.

YIG-Based Sensor System for Millisecond Time Range Magnetorelaxometry.

In the current study we propose a magneto-optical system for registration and analysis of magnetic nano- and microparticles magnetic relaxation. The core of our system is the novel compact magnetometer based on an yttrium-iron garnet film and working at room temperature. The sensor demonstrates sensitivity of 35 pT/√{Hz} at 79 Hz and recovery time less than 100 µs, which allows to register quite fast magnetic relaxations of a low amplitude.

Yttrium-Iron Garnet Film Magnetometer for Registration of Magnetic Nano- and Submicron Particles: In Vitro and In Vivo Studies.

In the current article, we present a new kind of magnetometer for quantitative detection of magnetic objects (magnetic nano- and submicron particles) in biological fluids and tissues. The sensor is based on yttrium-iron garnet film with optical signal registration system. Inheriting the working principle of a fluxgate magnetometers, the sensor works at a room-temperature, its wide dynamic range allows the measurements in an unshielded environment.

Yttrium-Iron Garnet Magnetometer in MEG: Advance towards Multi-Channel Arrays.

Recently, a new kind of sensor applicable in magnetoencephalography (MEG) has been presented: a solid-state yttrium-iron garnet magnetometer (YIGM). The feasibility of yttrium-iron garnet magnetometers (YIGMs) was demonstrated in an alpha-rhythm registration experiment. In this paper, we propose the analysis of lead-field matrices for different possible multi-channel on-scalp sensor layouts using YIGMs with respect to information theory.

Optical registration of a coherent magnon state outside of the excitation region.

Magnons have demonstrated enormous potential for the next generation of information technology and quantum computing. In particular, the coherent state of magnons resulting from their Bose-Einstein condensation (mBEC) is of great interest. Typically, mBEC is formed in the magnon excitation region.

Magneto-optical imaging of coherent spin dynamics in ferrites.

The explosive development of quantum magnonics is associated with the possibility of its use as macroscopic quantum systems. In particular, they can find an application for quantum computing processors and other devices. The recently discovered phenomenon of magnon Bose-Einstein condensation and coherent precession of magnetization can be used for these purposes.

Micromagnetic modeling of magnon coherent states in a nonuniform magnetic field.

Quantum magnonics is an emerging research field, with great potential for applications in a magnon based quantum technologies, including quantum computing, processing and encoding information. Magnon correlation and quantum entanglement are the main concepts in many quantum technologies under development. Of particular interest is the magnon Bose condensation.

Evolution of MEG: A first MEG-feasible fluxgate magnetometer.

In the current article, we present the first solid-state sensor feasible for magnetoencephalography (MEG) that works at room temperature. The sensor is a fluxgate magnetometer based on yttrium-iron garnet films (YIGM). In this feasibility study, we prove the concept of usage of the YIGM in terms of MEG by registering a simple brain induced field-the human alpha rhythm.

Quantum paradigm of the foldover magnetic resonance.

The explosive development of quantum magnonics requires the consideration of several previously known effects from a new angle. In particular, taking into account the quantum behavior of magnons is essential at high excitations of the magnetic system, under the conditions of the so-called phenomenon of "foldover" (bi-stable) magnetic resonance. Previously, this effect was considered in the quasi-classical macrospin approximation.

Optical excitation of spin waves in epitaxial iron garnet films: MSSW vs BVMSW.

In most of the previous studies of the spin wave optical generation in magnetic dielectrics, the backward volume spin waves were excited. Here we modified the parameters of the circularly polarized optical pump beams emitted by femtosecond laser to reveal surface spin waves in bismuth iron garnet thin film. Beams that are larger than 10 μm in diameter generate both surface and volume spin waves with only one spectral peak near the ferromagnetic resonance.