Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood's Anomaly.

We demonstrate numerically how a spin wave (SW) beam obliquely incident on the edge of a thin film placed below a ferromagnetic stripe can excite leaky SWs guided along the stripe. During propagation, leaky waves emit energy back into the layer in the form of plane waves and several laterally shifted parallel SW beams. This resonance excitation, combined with interference effects of the reflected and re-emitted waves, results in the magnonic Wood's anomaly and a significant increase of the Goos-Hänchen shift magnitude. This yields a unique platform to control SW reflection and transdimensional magnonic router that can transfer SWs from a 2D platform into a 1D guided mode.

Influence of Dzyaloshinskii-Moriya interaction and perpendicular anisotropy on spin waves propagation in stripe domain patterns and spin spirals.

Texture-based magnonics focuses on the utilization of spin waves in magnetization textures to process information. Using micromagnetic simulations, we study how (1) the dynamic magnetic susceptibility, (2) dispersion relations, and (3) the equilibrium magnetic configurations in periodic magnetization textures in a ultrathin ferromagnetic film in remanence depend on the values of the Dzyaloshinskii-Moriya interaction and the perpendicular magnetocrystalline anisotropy. We observe that for large Dzyaloshinskii-Moriya interaction values, spin spirals with periods of tens of nanometers are the preferred state; for small Dzyaloshinskii-Moriya interaction values and large anisotropies, stripe domain patterns with over a thousand times larger period are preferable. We observe and explain the selectivity of the excitation of resonant modes by a linearly polarized microwave field. We study the propagation of spin waves along and perpendicular to the direction of the periodicity. For propagation along the direction of the periodicity, we observe a bandgap that closes and reopens, which is accompanied by a swap in the order of the bands. For waves propagating in the perpendicular direction, some modes can be used for unidirectional channeling of spin waves. Overall, our findings are promising in sensing and signal processing applications and explain the fundamental properties of periodic magnetization textures.

Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers.

Reconfigurable magnetization textures offer control of spin waves with promising properties for future low-power beyond-CMOS systems. However, materials with perpendicular magnetic anisotropy (PMA) suitable for stable magnetization-texture formation are characterized by high damping, which limits their applicability in magnonic devices. Here, we propose to overcome this limitation by using hybrid structures, i.e., a PMA layer magnetostatically coupled to a low-damping soft ferromagnetic film. We experimentally show that a periodic stripe-domain texture from a PMA layer is imprinted upon the soft layer and induces a nonreciprocal dispersion relation of the spin waves confined to the low-damping film. Moreover, an asymmetric bandgap features the spin-wave band diagram, which is a clear demonstration of collective spin-wave dynamics, a property characteristic for magnonic crystals with broken time-reversal symmetry. The composite character of the hybrid structure allows for stabilization of two magnetic states at remanence, with parallel and antiparallel orientation of net magnetization in hard and soft layers. The states can be switched using a low external magnetic field; therefore, the proposed system obtains an additional functionality of state reconfigurability. This study offers a link between reconfigurable magnetization textures and low-damping spin-wave dynamics, providing an opportunity to create miniaturized, programmable, and energy-efficient signal processing devices operating at high frequencies.

Resonant subwavelength control of the phase of spin waves reflected from a Gires-Tournois interferometer.

Subwavelength resonant elements are essential building blocks of metamaterials and metasurfaces, which have revolutionized photonics. Despite similarities between different wave phenomena, other types of interactions can make subwavelength coupling significantly distinct; its investigation in their context is therefore of interest both from the physics and applications perspective. In this work, we demonstrate a fully magnonic Gires-Tournois interferometer based on a subwavelength resonator made of a narrow ferromagnetic stripe lying above the edge of a ferromagnetic film. The bilayer formed by the stripe and the film underneath supports two propagative spin-wave modes, one strongly coupled with spin waves propagating in the rest of the film and another almost completely reflected at the ends of the bilayer. When the Fabry-Perot resonance conditions for this mode are satisfied, the weak coupling between both modes is sufficient to achieve high sensitivity of the phase of waves reflected from the resonator to the stripe width and, more interestingly, also to the stripe-film separation. Such spin-wave phase manipulation capabilities are a prerequisite for the design of spin-wave metasurfaces and may stimulate development of magnonic logic devices and sensors detecting magnetic nanoparticles.

Real-Space Observation of Magnon Interaction with Driven Space-Time Crystals.

The concept of space-time crystals (STC), i.e., translational symmetry breaking in time and space, was recently proposed and experimentally demonstrated for quantum systems. Here, we transfer this concept to magnons and experimentally demonstrate a driven STC at room temperature. The STC is realized by strong homogeneous microwave pumping of a micron-sized permalloy (Py) stripe and is directly imaged by scanning transmission x-ray microscopy (STXM). For a fundamental understanding of the formation of the STC, micromagnetic simulations are carefully adapted to model the experimental findings. Beyond the mere generation of a STC, we observe the formation of a magnonic band structure due to back folding of modes at the STC's Brillouin zone boundaries. We show interactions of magnons with the STC that appear as lattice scattering, which results in the generation of ultrashort spin waves (SW) down to 100-nm wavelengths that cannot be described by classical dispersion relations for linear SW excitation. We expect that room-temperature STCs will be useful to investigate nonlinear wave physics, as they can be easily generated and manipulated to control their spatial and temporal band structures.

Spin-wave spectroscopy of individual ferromagnetic nanodisks.

The increasing demand for nanoscale magnetic devices requires development of 3D magnetic nanostructures. In this regard, focused electron beam induced deposition (FEBID) is a technique of choice for direct-writing of complex nano-architectures with applications in nanomagnetism, magnon spintronics, and superconducting electronics. However, intrinsic properties of nanomagnets are often poorly known and can hardly be assessed by local optical probe techniques. Here, an original spatially resolved approach is demonstrated for spin-wave spectroscopy of individual circular magnetic elements with sample volumes down to about 10-3 µm3. The key component of the setup is a coplanar waveguide whose microsized central part is placed over a movable substrate with well-separated CoFe-FEBID nanodisks which exhibit standing spin-wave resonances. The circular symmetry of the disks allows for the deduction of the saturation magnetization and the exchange stiffness of the material using an analytical theory. A good correspondence between the results of analytical calculations and micromagnetic simulations is revealed, indicating a validity of the used analytical model going beyond the initial thin-disk approximation used in the theoretical derivation. The presented approach is especially valuable for the characterization of direct-write magnetic elements opening new horizons for 3D nanomagnetism and magnonics.

Demonstration of k-vector selective microscopy for nanoscale mapping of higher order spin wave modes.

As a potential route towards beyond CMOS computing magnonic waveguides show outstanding properties regarding fundamental wave physics and data transmission. Here, we use time resolved scanning transmission X-ray microscopy to directly observe spin waves in magnonic permalloy waveguides with nanoscale resolution. Additionally, we demonstrate an approach for k-vector selective imaging to deconvolute overlapping modes in real space measurements. Thereby, we observe efficient excitation of symmetric and antisymmetric modes. The profiles of higher order modes that arise from sub-micron confinement are precisely mapped out and compared to analytical models. Thus, we lay a basis for the design of multimode spin wave transmission systems and demonstrate a general technique for k-specific microscopy that can also be used beyond the field of magnonics.

The impact of birth anesthesia on the parameters of oxygenation and acid-base balance in umbilical cord blood.

Background: There is a great number of studies dealing with the impact of birth anesthesia on the course of labor and condition of the newborn. The aim of this study was to investigate the impact of birth anesthesia on the parameters of oxygenation and acid-base balance in umbilical cord blood.Methods: Subjects were divided into four groups: vaginal delivery without anesthesia, vaginal delivery with epidural anesthesia, delivery by cesarean section under a subarachnoid block, and delivery by cesarean section under general anesthesia. The study included mothers aged 18-45 and their newborns born from a singleton normal pregnancy lasting 37-42 weeks, calculating the date of birth according to Naegele's Rule, which was confirmed by ultrasound assessment. The inclusion criteria were a birth weight between 2800 and 4100 gResults: Hematocrit, total hemoglobin, blood oxygen capacity and carboxyhemoglobin content (umbilical artery and vein mean values respectively in all study groups: 41.9 and 42.6%, 14.3 and 14.5 g/dl, 19.3 and 19.6 ml/dl) were similar in all groups and did not correlate with pH in either group. The mean pH value of umbilical cord arterial blood in the "vaginal delivery with epidural anesthesia" group was 7.27 and was significantly the lowest (p < .05) of all the examined groups, in the remaining groups, the mean values ranged between 7.29 and 7.30. Hemoglobin oxygen saturation, oxygenated hemoglobin content, and total oxygen content in umbilical cord blood were statistically significant (p < .001), almost twice as high in cesarean sections under general anesthesia than in cases of regional anesthesia regardless of the method of delivery. Vaginal deliveries had intermediate values of oxygenation parameters.Conclusion: Blood oxygenation of the fetus is a very good parameter to evaluate the clinical state of the baby. Due to most common hypotension of the mother by the regional anesthesia (subarachnoid or epidural), which is compensated by the application of the vasoconstrictors or only by the fluids, it comes to decrease in the oxygen supply of the fetus. We consider in this study that the general anesthesia can be, in some cases, more indicated than the regional anesthesia. The decision of which kind of anesthesia should be used needs to be made by the anesthetists and also by the obstetrician because it can affect the neonatal state after the delivery. It also needs to be mentioned that the time between the start of the anesthesia and the extraction of the fetus by the cesarean section should be as short as possible.

Cesarean section after laparoscopic hysterosacropexy with Richardson's lateral repair and Burch operation-Case report.

INTRODUCTION: Pelvic floor disorders are common also in young patient population. Their quality of life is lessened because of their condition, but they would also like to avoid any complicated operations. The minimal invasive procedures and fertility sparing are very important. CASE PRESENTATION: 32 year old caucasian female (BMI: 22,6) was admitted to our clinic in August 2016 with the following symptoms: the feeling of a foreign body in the vagina, prolapse of the bladder and stage II stress urinary incontinence. She had 2 vaginal deliveries. A gynecological examination of the pelvic organ prolapse was classified as follows: prolapse of the uterus POP-Q II, and a cystocele with a lateral defect POP-Q III, after reposition of uterus cystocele POP-Q II, urethrocele, positive cough test. She underwent a laparoscopic hysteropexy with lateral repair and Burch operation. Effect of the operation was satisfied. It revealed an improvement in the QoL-Questionnaire PIFQ-7. Pregnancy in 2018 was delivered by cesarean section. The effect of the prolapse operation was not affected and the quality of life maintained. CONCLUSION: Laparoscopic hysteropexy should be a standard procedure for the repair of a level I defect in young patients, particularly as a fertility sparing procedure.

Laparoscopic hysterosacropexy in case of total uterus prolapse - case report.

INTRODUCTION: Due to the many advances in laparoscopic surgery in urogynecology, various uterus-preserving techniques are increasingly being used in treatment. The following is a report of the case of a 43-year-old female with uterine prolapse POP-Q 4. This patient successfully underwent a minimally invasive laparoscopic procedure while preserving the uterus. PRESENTATION OF CASE: A 43-year-old caucasian female who was suffering from prolapse of the uterus POP-Q 4, overflow incontinence, dysuria and urinary retention was admitted to our department for the purpose of diagnostic tests and operative treatment. A gynecological examination showed a protruded hernial sac with the complete, normal sized uterus which had a thick appearance. The hernial sac also contained parts of the urinary bladder and intestines. Pelvic organ prolapse was classified as follows: prolapse of the uterus POP-Q 4. After repositioning the uterus with Kristeller specula we found a cystocele POP-Q 1 and a rectocele POP-Q 1. We also discovered a defect in the perineal region. Considering the patient's age and ASA Score 1, minimally invasive treatment was proposed: laparoscopic hysterosacropexy with perineoplasty. DISCUSSION: Transabdominal sacrocolpopexy is associated with a low recurrence rate and also lower rates of dyspareunia when compared with vaginal sacrospinal colpopexy. Both sacrocolpopexy and implantation of anterior vaginal polypropylene mesh have better success rates and a lower rate of reoperation than vaginal uterosacral suspension. In level I defects, the right approach seems to be sacropexy. In this technique, the sacrouterine ligament is restored by recreating a ligament with polypropylene mesh. CONCLUSION: Laparoscopic sacrohysteropexy seems to be a good alternative in the treatment of uterus prolapse. It can also be viewed as a possible alternative for apical defect POP Q III or IV.

Polarization tunable all-dielectric color filters based on cross-shaped Si nanoantennas.

Polarization sensitive and insensitive color filters have important applications in the area of nano-spectroscopy and CCD imaging applications. Metallic nanostructures provide an efficient way to design and engineer ultrathin color filters. These nanostructures have capability to split the white light into fundamental colors and enable color filters with ultrahigh resolution but their efficiency can be restricted due to high losses in metals especially at the visible wavelengths. In this work, we demonstrate all-dielectric color filters based on Si nanoantennas, which are sensitive to incident-wave polarization and, thus, tunable with the aid of polarization angle variation. Two different information can be encoded in two different polarization states in one nanostructure. The nanoantenna based pixels are highly efficient and can provide high quality of colors, in particular, due to low losses in Si at optical frequencies. We experimentally demonstrate that a variety of colors can be achieved by changing the physical size of the nonsymmetric cross-shaped nanoantennas. The proposed devices allow to cover an extended gamut of colors on CIE-1931 chromaticity diagram owing to the existence of high-quality resonances in Si nanoantennas. Significant tunability of the suggested color filters can be achieved by varying polarization angle in both transmission and reflection mode. Additional tunability can be obtained by switching between transmission and reflection modes.