440 research outputs found
Anomalous Hall voltage rectification and quantized spin-wave excitation induced by the simultaneous dc- and rf-current application in Ni81Fe19 wire
An anomalous Hall effect and rectification of a Hall voltage are observed by
applying a radio-frequency (rf) current through a single-layered ferromagnetic
wire located on a coplanar waveguide. The components of the magnetization
precession, both in and perpendicular to the plane, can be detected via the
Hall voltage rectification of the rf current by incorporating an additional
direct (dc) current. In this paper, we propose a phenomenological model, which
describes the time-dependent anisotropic magnetoresistance and time-dependent
planer Hall effect. The nonlinearity of the spin dynamics accompanied by
spin-waves as functions of rf and dc currents is also studied, as well as those
of the magnitude and orientation of the external magnetic field.Comment: 42 pages, 5 figures, submitte
Megabits secure key rate quantum key distribution
Quantum cryptography (QC) can provide unconditional secure communication
between two authorized parties based on the basic principles of quantum
mechanics. However, imperfect practical conditions limit its transmission
distance and communication speed. Here we implemented the differential phase
shift (DPS) quantum key distribution (QKD) with up-conversion assisted hybrid
photon detector (HPD) and achieved 1.3 M bits per second secure key rate over a
10-km fiber, which is tolerant against the photon number splitting (PNS)
attack, general collective attacks on individual photons, and any other known
sequential unambiguous state discrimination (USD) attacks.Comment: 14 pages, 4 figure
Broadband ferromagnetic resonance of Ni81Fe19 wires using a rectifying effect
The broadband ferromagnetic resonance measurement using the rectifying effect
of Ni81Fe19 wire has been investigated. One wire is deposited on the center
strip line of the coplanar waveguide (CPW) and the other one deposited between
two strip lines of CPW. The method is based on the detection of the
magnetoresistance oscillation due to the magnetization dynamics induced by the
radio frequency field. The magnetic field dependences of the resonance
frequency and the rectification spectrum are presented and analytically
interpreted on the standpoint of a uniform magnetization precession model.Comment: 33pages, 8 figures. submitte
An Effective Reduction of Critical Current for Current-Induced Magnetization Switching by a Ru Layer Insertion in an Exchange-Biased Spin-Valve
Recently it has been predicted that a spin-polarized electrical current
perpendicular-to-plane (CPP) directly flowing through a magnetic element can
induce magnetization switching through spin-momentum transfer. In this letter,
the first observation of current-induced magnetization switching (CIMS) in
exchange-biased spin-valves (ESPVs) at room temperature is reported. The ESPVs
show the CIMS behavior under a sweeping dc current with a very high critical
current density. It is demonstrated that a thin Ruthenium (Ru) layer inserted
between a free layer and a top electrode effectively reduces the critical
current densities for the CIMS. An "inverse" CIMS behavior is also observed
when the thickness of the free layer increases.Comment: 15 pages with figure
Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective
This Report has a number of inter-related general purposes. One is to explore the extent to which food, nutrition, physical activity, and body composition modify the risk of cancer, and to specify which factors are most important. To the extent that environmental factors such as food, nutrition, and physical activity influence the risk of cancer, it is a preventable disease. The Report specifies recommendations based on solid evidence which, when followed, will be expected to reduce the incidence of cancer
- β¦