Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMicrostrip resonator for microwaves with controllable polarization
334
0
0.0
(
0
)
Added by
Thiago P. Mayer Alegre
Publication date
2007
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
In this work the authors implemented a resonator based upon microstrip cavities that permits the generation of microwaves with arbitrary polarization. Design, simulation, and implementation of the resonators were performed using standard printed circuit boards. The electric field distribution was mapped using a scanning probe cavity perturbation technique. Electron spin resonance using a standard marker was carried out in order to verify the polarization control from linear to circular.
rate research
Read More
Based on interrelation between the thermodynamic and electromechanical phenomena in superfluid helium, the explanation of experimentally found features of microwave interaction in the frequency range of 40-200 GHz is given. Due to fast roton-roton and roton-phonon interactions resonant excitation on frequency correspond to minimal roton energy relaxes and forms a wide pedestal. Alongside these fast processes, there are also slower processes of rotons scattering by microwave photons taking place, which lead to additional absorption of energy of resonant microwaves and to the appearance of a narrow resonant peak on the background of a wide pedestal. The theoretical explanation of the influence which streams exert on resonant absorption of microwaves is given. The critical velocity of stream at which absorption of microwaves was replaced by their radiation is found.
We investigate the magnetic hysteresis of a superconducting microstrip resonator with a high edge barrier. We measure the magnetic hysteresis while either sweeping a magnetic field or tuning the edge barrier by high microwave current. We show that the magnetic hysteresis of such a device is qualitatively different from that of one without an edge barrier and can be understood based on the generalized critical-state model. In particular, we propose and demonstrate a simple and intuitive method that relies on a plot of the quality factor versus the resonance frequency for revealing the physical processes behind those hysteretic behaviors. Based on this, we find that the interplay between the Meisser current and vortex pinning is essential for understanding the magnetic hysteresis of such a device.
In this article we discuss the design and implementation of a novel microstrip resonator which allows for the absolute control of the microwaves polarization degree for frequencies up to 30 GHz. The sensor is composed of two half-wavelength microstrip line resonators, designed to match the 50 Ohms impedance of the lines on a high dielectric constant GaAs substrate. The line resonators cross each other perpendicularly through their centers, forming a cross. Microstrip feed lines are coupled through small gaps to three arms of the cross to connect the resonator to the excitation ports. The control of the relative magnitude and phase between the two microwave stimuli at the input ports of each line allows for tuning the degree and type of polarization of the microwave excitation at the center of the cross resonator. The third (output) port is used to measure the transmitted signal, which is crucial to work at low temperatures, where reflections along lengthy coaxial lines mask the signal reflected by the resonator. EPR spectra recorded at low temperature in an S= 5/2 molecular magnet system show that 82%-fidelity circular polarization of the microwaves is achieved over the central area of the resonator.
The electron transport of different conical valleys is investigated in graphene with extended line-defects. Intriguingly, the electron with a definite incident angle can be completely modulated into one conical valley by a resonator which consists of several paralleling line-defects. The related incident angle can be controlled easily by tuning the parameters of the resonator. Therefore, a controllable 100% valley polarization, as well as the detection of the valley polarization, can be realized conveniently by tuning the number of line-defects and the distance between two nearest neighbouring line-defects. This fascinating finding opens a way to realize the valley polarization by line-defects. With the advancement of experimental technologies, this resonator is promising to be realized and thus plays a key role in graphene valleytronics.
We analyze coherent transport of photons, which propagate in a one-dimensional coupled-resonator waveguide (CRW) and are scattered by a controllable two-level system located inside the CRW. Our approach, which uses discrete coordinates, unifies low and high energy effective theories for single photon scattering. We show that the controllable two-level system can behave as a quantum switch for the coherent transport of photons. This study may inspire new electro-optical single-photon quantum devices. We also suggest an experimental setup based on superconducting transmission line resonators and qubits
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
