Bi-quadratic magnetoelectric coupling in underdoped La_2CuO_{4+x}

The recent discovery of relaxor ferroelectricity and magnetoelectric effect in lightly doped cuprate material La_2CuO_{4+x} has provided a number of questions concerning its theoretical description. It has been argued using a Ginzburg-Landau free energy approach that the magnetoelectric effect can be explained by the presence of bi-quadratic interaction terms in the free energy. Here, by using the same free energy functional, we study the variety of behavior which can emerge in the electric polarization under an external magnetic field. Subsequently, we discuss the role of Dzyaloshinskii-Moriya interaction in generating this magnetoelectric response. This work is particularly relevant for such relaxor systems where the material-dependent parameters would be affected by changes in e.g. chemical doping or cooling rate.Comment: 8 pages, 2 figures. arXiv admin note: text overlap with arXiv:1112.152

Perilaku Dan Motivasi Komplain Konsumen Terhadap Restoran-restoran Di Surabaya

Penelitian ini ditunjukan untuk menguji perilaku, motivasi komplain, serta korelasi antara perilaku komplain dengan usia, jenis kelamin, dan tingkat pendidikan. Uji mean dilakukan untuk menguji tingginya perilaku komplain konsumen dan motivasi komplain konsumen dalam melakukan komplain dan uji chi square untuk menguji adanya korelasi antara perilaku komplain dengan usia, jenis kelamin, dan tingkat pendidikan. Berdasarkan hasil tes dapat disimpulkan bahwa: (1) Perilaku menceritakan pengalaman dan motivasi mengekspresikan emosi yang mana ditunjukkan dari hasil mean yang paling tinggi. (2) Usia tidak berkorelasi dengan perilaku komplain, sedangkan jenis kelamin dan tingkat pendidikan memiliki korelasi

Restaurant Revenue Management: Implementasi Di Restoran “X” Surabaya

Restaurant Revenue Management merupakan aplikasi dari sistem informasi dan strategi harga yang menjual tempat yang tepat kepada pelanggan yang tepat pada waktu yang tepat dan dalam jangka waktu yang tepat. Pengimplementasian restaurant revenue management dilakukan melalui tiga langkah yang bertujuan untuk mengidentifikasikan dan menyelesaikan permasalahan yang muncul dengan penggunaan dari strategi restaurant revenue management. Dalam pengimplementasiannya dilakukan langkah pertama yaitu menetapkan baseline yang bertujuan untuk mengetahui faktor-faktor yang mempengaruhi kegiatan restoran “X” yaitu average check, seat occupancy, RevPASH serta meal duration. Dilanjutkan dengan penerapan langkah kedua yaitu memahami drivers yang bertujuan untuk mengidentifikasi permasalahan-permasalahan yang ada berdasarkan langkah pertama dengan menggunakan fishbone diagram, lalu dilanjutkan dengan penerapan langkah ketiga yaitu membuat strategi revenue management yang bertujuan untuk memberikan strategi untuk membantu menyelesaikan permasalahan-permasalahan yang sudah teridentifikasi pada langkah kedua di Restoran “X” Surabay

Tendency of spherically imploding plasma liners formed by merging plasma jets to evolve toward spherical symmetry

Three dimensional hydrodynamic simulations have been performed using smoothed particle hydrodynamics (SPH) in order to study the effects of discrete jets on the processes of plasma liner formation, implosion on vacuum, and expansion. The pressure history of the inner portion of the liner was qualitatively and quantitatively similar from peak compression through the complete stagnation of the liner among simulation results from two one dimensional radiationhydrodynamic codes, 3D SPH with a uniform liner, and 3D SPH with 30 discrete plasma jets. Two dimensional slices of the pressure show that the discrete jet SPH case evolves towards a profile that is almost indistinguishable from the SPH case with a uniform liner, showing that non-uniformities due to discrete jets are smeared out by late stages of the implosion. Liner formation and implosion on vacuum was also shown to be robust to Rayleigh-Taylor instability growth. Interparticle mixing for a liner imploding on vacuum was investigated. The mixing rate was very small until after peak compression for the 30 jet simulation.Comment: 28 pages, 16 figures, submitted to Physics of Plasmas (2012

Magnetic field effects and magnetic anisotropy in lightly doped La_{2-x}Sr_xCuO_4

The effects of the application of a magnetic field on the diagonal stripe spin-glass phase is studied in lightly doped La_{2-x}Sr_xCuO_4 (x=0.014 and 0.024). With increasing magnetic field, the magnetic elastic intensity at the diagonal incommensurate (DIC) positions (1,\pm\epsilon,0) decreases as opposed to the increase seen in superconducting samples. This diminution in intensity with increasing magnetic field originates from a spin reorientation transition, which is driven by the antisymmetric exchange term in the spin Hamiltonian. On the other hand, the transition temperature, the incommensurability, and the peak width of the diagonal incommensurate correlations are not changed with magnetic field. This result suggests that the magnetic correlations are determined primarily by the charge disproportionation and that the geometry of the diagonal incommensurate magnetism is also determined by effects, that is, stripe formation which are not purely magnetic in origin. The Dzyaloshinskii-Moriya antisymmetric exchange is nevertheless important in determining the local spin structure in the DIC stripe phase.Comment: 7 pages, 5 figures, to appear in Phys. Rev.

Unusual magnetic susceptibility anisotropy in untwinned La_{2-x}Sr_xCuO_4 single crystals in the lightly-doped region

We present a study of the magnetic susceptibility in carefully detwinned La_{2-x}Sr_{x}CuO_4 single crystals in the lightly-doped region (x=0-0.03), which demonstrates a remarkable in-plane anisotropy of the spin system. This anisotropy is found to persist after the long-range antiferromagnetic (AF) order is destroyed by hole doping, suggesting that doped holes break the AF order into domains in which the spin alignment is kept essentially intact. It turns out that the freezing of the spins taking place at low temperatures is also notably anisotropic, implying that the "spin-glass" feature is governed by the domain structure as well.Comment: 4 pages, 3 figures, accepted for publication in Phys.Rev.Let