Spin interference effects in ring conductors subject to Rashba coupling

Quantum interference effects in rings provide suitable means for controlling spin at mesoscopic scales. Here we apply such control mechanisms to coherent spin-dependent transport in one- and two-dimensional rings subject to Rashba spin-orbit coupling. We first study the spin-induced modulation of unpolarized currents as a function of the Rashba coupling strength. The results suggest the possibility of all-electrical spintronic devices. Moreover, we find signatures of Berry phases in the conductance previously unnoticed. Second, we show that the polarization direction of initially polarized, transmitted spins can be tuned via an additional small magnetic control flux. In particular, this enables to precisely reverse the polarization direction at half a flux quantum. We present full numerical calculations for realistic two-dimensional ballistic microstructures and explain our findings in a simple analytical model for one-dimensional rings.Comment: 8 pages, 5 figures. Submitted to Phys. Rev. B, final versio

Coherent transport through graphene nanoribbons in the presence of edge disorder

We simulate electron transport through graphene nanoribbons of experimentally realizable size (length L up to 2 micrometer, width W approximately 40 nm) in the presence of scattering at rough edges. Our numerical approach is based on a modular recursive Green's function technique that features sub-linear scaling with L of the computational effort. We identify the influence of the broken A-B sublattice (or chiral) symmetry and of K-K' scattering by Fourier spectroscopy of individual scattering states. For long ribbons we find Anderson-localized scattering states with a well-defined exponential decay over 10 orders of magnitude in amplitude.Comment: 8 pages, 6 Figure

Analisis Kebutuhan Infrastruktur di Kecamatan Rasau Jaya Kabupaten Kubu Raya

Kecamatan Rasau Jaya merupakan salah satu kecamatan di Kabupaten Kubu Raya yang terletak tidak jauh dari ibukota provinsi Kalimantan Barat. Dengan luas wilayah 111,07 km2. Kecamatan Rasau Jaya terbagi menjadi 6 desa yang terdiri dari : Desa Rasau Jaya Umum, Desa Bintang Mas, Desa Rasau Jaya III, Desa Rasau Jaya I, Desa Rasau Jaya II dan Desa Pematang Tujuh. Kecamatan Rasau Jaya merupakan wilayah yang sedang berkembang dan merupakan wilayah yang sangat berpotensi karena merupakan wilayah yang dilalui jalur transportasi dari berbagai kecamatan menuju ibukota provinsi KalBar, Kota Pontianak. Adapun tujuan dari penelitian ini adalah mengidentifikasi sektor-sektor yang diprioritaskan sebagai fasilitas pelayanan, menghitung nilai aksesibilitas dengan metode Integrated Rural Accessibility Planning ( IRAP ), serta menentukan pendekatan penanganan/perbaikan akses penduduk desa. Dalam penelitian ini dilakukan suatu pengkajian mengenai perencanaan aksesibilitas pedesaan dengan menggunakan metode Integrated Rural Accessibility Planning (IRAP) yang dikembangkan oleh International Labour Organization (ILO). Pengumpulan data untuk metode IRAP ini dengan menggunakan kombinasi pengumpulan data berbasis interview/wawancara, warta berita terkini,observasi lapangan, dan pengisian kuisioner. Adapun sektor yang ditinjau dalam kuisioner ini antara lain : Sumber Tenaga Listrik, Sumber Air Bersih, Pendidikan, Kesehatan, Pasar, Komunikasi, Pemukiman, Pertanian dan Perkebunan. Hasil analisa penelitian menyimpulkan bahwa tingkatan nilai aksesibilitas pada sektor - sektor aksesibilitas Desa Rasau Jaya Umum, Desa Bintang Mas, Desa Rasau Jaya III, Desa Rasau Jaya I, Desa Rasau Jaya II dan Desa Pematang Tujuh untuk sembilan sektor yang di teliti memiliki nilai aksesibilitas yang bervariasi. Sektor prioritas suatu desa didapat dari hasil analisa yang ditentukan dari nilai aksesibilitas yang terbesar. Nilai aksesibilitas sektor prioritas di Kecamatan Rasau Jaya meliputi sektor pertanian di Desa Rasau Jaya Umum sebesar 11,679, sektor pertanian di Desa Bintang Mas sebesar 9,724, sektor pertanian di Desa Rasau Jaya III sebesar 11,143, sektor pertanian di Desa Rasau Jaya I sebesar 11,548, sektor pertanian di Desa Rasau Jaya II sebesar 13,123 dan sektor pendidikan di Desa Pematang Tujuh sebesar 10,329. Hasil analisis terbagi atas tiga klasifikasi, yaitu aksesibilitas fasilitas, aksesibilitas sarana transportasi dan aksesibilitas prasarana transportasi. Berdasarkan perbandingan nilai aksesibilitas antara komponen fasilitas, sarana dan prasarana transportasi untuk semua sektor maka pada 6 desa tersebut di ketahui bahwa memprioritaskan perbaikan/penanganan prasarana transportasi

Respons Pertumbuhan Bibit Kakao Terhadap Vermikompos Dan Pupuk P

Response of Cacao (Theobroma cacao L.) Seedlings Growth on Application of Vermicompost andP Fertilizer. The research was conducted to determine response of cacao seedlings growth onapplication of vermicompost and P fertilizer. The research carried out at Faculty of AgricultureUSU\u27s Experiment Land with a height of 25 metre above sea level on August until November 2012by using Randomized Block Design of two factors which is the first factors were vermicompost(0%, 25%, 50%, 75%) and the second factor were P fertilizer (0, 2, 4, 6 g/plant). The parametersobserved were seedling height, leaf number, stem diameter, total of leaf area, seedling wet weight,seedling dry weight, root wet weight, root dry weight and shoot root ratio. The results showed thatvermicompost has significant effects on seedling height, leaf number and seedling dry weight. Theapplication of P fertilizer and interaction of them had no significant effects on all parametersobserved

Pengaruh Citra Merek Dan Promosi Terhadap Keputusan Pembelian Mobil Suzuki APV (Studi Pada PT. Arindo Gedong Jembar Tegal)

This research is motivated by competition brand in Low car segment MPV. Suzuki brand car sales in 2013 based Gaikindo be in the top four nationally and has yet to reach a specified target. In particular, this study discusses the Low MPV Suzuki APV cars at PT . Arindo gedong Jembar Tegal that sales decreased in the last two years. The purpose of research to determine the influence of brand image and promotion on purchase decisions Suzuki APV (Studies in PT. Arindo Gedong Jembar Tegal). This research method is explanatory, data collection techniques by questionnaires, observation, and literature study. Purposive sampling technique is used with a sample of 78 people. The analysis technique used was qualitative and quantitative using validity, reliability test, correlation coefficient, simple and multiple regression analysis, the coefficient of determination, cross tabulation, and the significance test ( t test and F test ). Results and discussion showed a positive influence on the brand image on purchasing decisions. Promotion positive influence on purchase decisions. Brand image and promotion jointly positive influence on purchasing decisions. Suggestions in this study ,PT. Arindo Gedong Jembar should enhance the brand image of Suzuki APVby improve after-sales service, increase understanding of the explanation of product knowledge Suzuki APV, and also increases the intensity of the promotion through social media, outdoor media, sponsorship and giving special training about technique of delivering information for salesman and verbally skills in conveying information in order to increase the purchase of Suzuki APV cars

Kajian Karakteristik Profil Pantai dengan Menggunakan Metode Equilibrium Beach Profile di Kecamatan Sinaboi Kabupaten Rokan Hilir

Coastal area is a very vulnerable to changes, because dynamic movement which are cause by the wave. A wave move bring a very easy basic particle coast and make errotion andaccresion in some area of coast. But, a coast will be return into a basic form if they had a balance character. Equilibrium Beach Profile (EBP) method is empirical correlation a scale parameter and the sediment size or fall velocity allow computation z = Ax2/3. Thismethod first time applicated by Robert G Dean in the beach California, United States. A purpose of research is want to know a balance of the coast in Sinaboi, Rokan Hilir with Equilibrium Beach Profile method. From analysis cross section data in some area, a slope formed by Equilibrium Beach Profile method almost approaching existing slope. A some cross section data which has a difference with existing slope and then justified a parameter