Perfect valley filter in strained graphene with single barrier region

We present a single barrier system to generate pure valley-polarized current in monolayer graphene. A uniaxial strain is applied within the barrier region, which is delineated by localized magnetic field created by ferromagnetic stripes at the regions boundaries. We show that under the condition of matching magnetic field strength, strain potential, and Fermi energy, the transmitted current is composed of only one valley contribution. The desired valley current can transmit with zero reflection while the electrons from the other valley are totally reflected. Thus, the system generates pure valley-polarized current with maximum conductance. The chosen parameters of uniaxial strain and magnetic field are in the range of experimental feasibility, which suggests that the proposed scheme can be realized with current technology

Constructing Quantum Logic Gates Using q-Deformed Harmonic Oscillator Algebras

We study two-level q-deformed angular momentum states and us- ing q-deformed harmonic oscillators, we provide a framework for con- structing qubits and quantum gates. We also present the construction of some basic quantum gates including CNOT, SWAP, Toffoli and Fredkin.Comment: Slightly modified version of the accepted manuscrip

Energy, exergy, sustainability, and economic analyses of a grid-connected solar power plant consisting of bifacial PV modules with solar tracking system on a single axis

This study presents the energy, exergy, sustainability and exergoeconomic analysis of a grid-connected solar power plant with a power capacity of 226.4 MWe with a single axis solar tracking system consisting of monocrystalline and bifacial solar panels manufactured with half-cut technology. This solar power plant is located in Karapınar district of Konya province in Türkiye, between 37°45 and 37°47 north latitudes and 33°33 and 33°35 east longitudes. Based on the first and second laws of thermodynamics, the 6-month average values of the energy efficiency, maximum electrical efficiency, power conversion efficiency, exergy efficiency, sustainability index, thermoeconomic, and exergoeconomic parameters of the power plant were evaluated in detail. As a result of the energy and exergy analyses, the energy efficiency, maximum electricity efficiency, power conversion efficiency, and exergy efficiency of the plant were found to be 75.50%, 36.42%, 22.34%, and 21.98%, respectively. The sustainability index of the power plant is 1.29. Thermoeconomic and exergoeconomic parameter values were calculated as 2.43 W/$and 2.32 W/$, respectively, using EXCEM method

Küçük dikey eksenli rüzgâr türbini için basit kontrol tasarımı (Simple control design for a small vertical axis wind turbine)

Bu makalede, küçük dikey eksenli rüzgâr türbinin elde ettiği enerjiyi maksimize edecek basit bir kontrolör tasarlanmıştır. Bu önerilen kontrol algoritmasının amacı mevcut sistemlere kıyasla daha basit bir yapıda olmasıdır. Algoritma kontrol işlemini sisteme uygulanan yük katsayısını önceden belirlenen değer aralıklarında müdahalede bulunarak yapabilmektedir. Bunu yapmak için önceden enerjiyi maksimize eden bir optimizasyon yöntemiyle belirlenmiş olan sınır değerlerinden faydalanmaktadır. Bu makalede, değişik simülasyonlar sonucu elde edilen enerjiyi maksimize ederken, basitleştirilmiş bir dikey eksenli rüzgâr türbini modeli kullanılmıştır

Quantum dots formed in three-dimensional Dirac semimetal Cd3_3As2_2 nanowires

We demonstrate quantum dot (QD) formation in three-dimensional Dirac semimetal Cd$_{3}$As$_{2}$ nanowires using two electrostatically tuned p$-$n junctions with a gate and magnetic fields. The linear conductance measured as a function of gate voltage under high magnetic fields is strongly suppressed at the Dirac point close to zero conductance, showing strong conductance oscillations. Remarkably, in this regime, the Cd$_{3}$As$_{2}$ nanowire device exhibits Coulomb diamond features, indicating that a clean single QD forms in the Dirac semimetal nanowire. Our results show that a p$-$type QD can be formed between two n$-$type leads underneath metal contacts in the nanowire by applying gate voltages under strong magnetic fields. Analysis of the quantum confinement in the gapless band structure confirms that p$-$n junctions formed between the p$-$type QD and two neighboring n$-$type leads under high magnetic fields behave as resistive tunnel barriers due to cyclotron motion, resulting in the suppression of Klein tunneling. The p$-$type QD with magnetic field-induced confinement shows a single hole filling. Our results will open up a route to quantum devices such as QDs or quantum point contacts based on Dirac and Weyl semimetals