An all-electrical torque differential magnetometer operating under ambient conditions

An all-electrical torque differential magnetometry (also known as cantilever magnetometry) setup employing piezoelectric quartz tuning forks is demonstrated. The magnetometer can be operated under ambient conditions as well as low temperatures and pressures. It extends the allowed specimen mass range up to several 10 $\mu$g without any significant reduction in the sensitivity. Operation under ambient conditions and a simple all-electrical design of the magnetometer should allow for an easy integration with other experimental setups. The uniaxial magnetic anisotropy of a 25 $\mu$m diameter iron wire, measured under ambient conditions with a high signal to noise ratio, was found to be in good agreement with its literature value. Further applications of the technique are discussed.Comment: 9 two-column pages, 9 figure

Early detection and efficient therapy of cardiac angiosarcoma due to routine transesophageal echocardiography after cerebrovascular stroke

Primary malignant cardiac tumors (cardiac angiosarcomas) are exceedingly rare. Since there are initially nonspecific or missing symptoms, these tumors are usually diagnosed only in an advanced, often incurable stage, after the large tumor mass elicits hemodynamic obstructive symptoms. A 59-year-old female presented with symptoms of cerebral ischemia. A computed tomography (CT) scan showed changes suggestive of stroke. Transesophageal echocardiography revealed an inhomogeneous, medium-echogenic, floating mass at the roof of the left atrium near the mouth of the right upper pulmonary vein, indicative of a thrombus. At surgery, a solitary tumor was completely enucleated. Histologically, cardiac angiosarcoma was diagnosed. The patient received adjuvant chemotherapy and was free of symptoms and recurrence of disease at 14 months follow-up. Due to the fortuitous appearance of clinical signs indicative of stroke, cardiac angiosarcoma was diagnosed and effectively treated at an early, nonmetastatic, and therefore potentially curable stage. Although cardiac angiosarcoma is a rare disease, it should be taken into consideration as a potential cause of cerebral embolic disease

Sign of inverse spin Hall voltages generated by ferromagnetic resonance and temperature gradients in yttrium iron garnet|platinum bilayers

We carried out a concerted effort to determine the absolute sign of the inverse spin Hall effect voltage generated by spin currents injected into a normal metal. We focus on yttrium iron garnet (YIG)|platinum bilayers at room temperature, generating spin currents by microwaves and temperature gradients. We find consistent results for different samples and measurement setups that agree with theory. We suggest a right-hand-rule to define a positive spin Hall angle corresponding to with the voltage expected for the simple case of scattering of free electrons from repulsive Coulomb charges.Comment: incorporated additions from the published versio

High cooperativity in coupled microwave resonator ferrimagnetic insulator hybrids

We report the observation of strong coupling between the exchange-coupled spins in gallium-doped yttrium iron garnet and a superconducting coplanar microwave resonator made from Nb. The measured coupling rate of 450 MHz is proportional to the square-root of the number of exchange-coupled spins and well exceeds the loss rate of 50 MHz of the spin system. This demonstrates that exchange coupled systems are suitable for cavity quantum electrodynamics experiments, while allowing high integration densities due to their extraordinary high spin densities. Our results furthermore show, that experiments with multiple exchange-coupled spin systems interacting via a single resonator are within reach.Comment: 5 pages, 3 figure