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Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Elastic Properties Of The Zintl Ferromagnet Yb14mnsb11, Sriparna Bhattacharya, D C. Marinescu, James R. Morris, Ivan A. Sergienko, Brian Sales, David Madrus, Veerle Keppens
Elastic Properties Of The Zintl Ferromagnet Yb14mnsb11, Sriparna Bhattacharya, D C. Marinescu, James R. Morris, Ivan A. Sergienko, Brian Sales, David Madrus, Veerle Keppens
Domnita Catalina Marinescu
We report measurements of the elastic moduli as a function of temperature (5–300) K and magnetic field (0–2 T) for the Zintl ferromagnet Yb14MnSb11, which is believed to be a rare example of an underscreened Kondo lattice. The elastic moduli measured below the Curie temperature in this complex ferromagnet exhibit unusual lattice stiffening that is independent of the magnetic field and can be adequately modeled using the Landau theory.
Nonadiabatic Generation Of A Pure Spin Current In A One-Dimensional Quantum Ring With Spin-Orbit Interaction, Marian Nita, D C. Marinescu, Andrei Manolescu, Vidar Gudmundsson
Nonadiabatic Generation Of A Pure Spin Current In A One-Dimensional Quantum Ring With Spin-Orbit Interaction, Marian Nita, D C. Marinescu, Andrei Manolescu, Vidar Gudmundsson
Domnita Catalina Marinescu
We demonstrate the theoretical possibility of obtaining a pure spin current in a 1D ring with spin-orbit interaction by irradiation with a nonadiabatic, two-component terahertz laser pulse, whose spatial asymmetry is reflected by an internal phase difference φ. The solutions of the equation of motion for the density operator are obtained for a spin-orbit coupling linear in the electron momentum (Rashba) and they are used to calculate the time-dependent charge and spin currents. We find that there are critical values of φ at which the charge current disappears, while the spin current reaches a maximum or a minimum value.
Weak Localization In A Lateral Superlattice With Rashba And Dresselhaus Spin-Orbit Interaction, D C. Marinescu, Andrei Manolescu
Weak Localization In A Lateral Superlattice With Rashba And Dresselhaus Spin-Orbit Interaction, D C. Marinescu, Andrei Manolescu
Domnita Catalina Marinescu
We calculate the weak localization (WL) correction to the conductivity of a lateral superlattice (LSL) with Rashba (R)-Dresselhaus (D) spin-orbit interaction (SOI). The superlattice is modeled as a sequence of parallel wires that support tunneling between adjacent sites, leading to the formation of extended Bloch states along its axis and a miniband in the energy spectrum. Our results, obtained by calculating the eigenvalues of the Cooperon operator in the diffusion approximation, indicate that the electron dephasing rate that determines the antilocalization correction is enhanced by a term proportional with the LSL potential and the bandwidth. Within the same formalism, the …
Topological Thermoelectric Effects In Spin-Orbit Coupled Electron- And Hole-Doped Semiconductors, E Dumitrescu, Chuanwei Zhang, D C. Marinescu, Sumanta Tewari
Topological Thermoelectric Effects In Spin-Orbit Coupled Electron- And Hole-Doped Semiconductors, E Dumitrescu, Chuanwei Zhang, D C. Marinescu, Sumanta Tewari
Domnita Catalina Marinescu
We compute the intrinsic contributions to the Berry-phase mediated anomalous Hall and Nernst effects in electron- and hole-doped semiconductors in the presence of an in-plane magnetic field as well as Rashba and Dresselhaus spin-orbit couplings. For both systems we find that the regime of chemical potential which supports the topological superconducting state in the presence of the superconducting proximity effect can be characterized by plateaus in the topological Hall and Nernst coefficients flanked by well-defined peaks marking the emergence of the topological regime. The plateaus arise from a clear momentum space separation between the region where the Berry curvature is …
Thermal Conductance Of A Two-Channel Kondo Model, C P. Moca, A Roman, D C. Marinescu
Thermal Conductance Of A Two-Channel Kondo Model, C P. Moca, A Roman, D C. Marinescu
Domnita Catalina Marinescu
A theory of thermal transport in a two-channel Kondo system, such as the one formed by a small quantum dot coupled to two leads and to a larger dot, is formulated. The interplay of the two screening constants allow an exploration of the Fermi liquid and non-Fermi liquid regimes. By using analytical, as well as numerical, renormalization group methods, we study the temperature dependence of the thermal conductance and the Lorentz number. We find that in the low-temperature limit, the Lorentz number attains its universal value, irrespective of the nature of the ground state.
Electronic Charge And Spin Density Distribution In A Quantum Ring With Spin-Orbit And Coulomb Interactions, Csaba Daday, Andrei Manolescu, D C. Marinescu, Vidar Gudmundsson
Electronic Charge And Spin Density Distribution In A Quantum Ring With Spin-Orbit And Coulomb Interactions, Csaba Daday, Andrei Manolescu, D C. Marinescu, Vidar Gudmundsson
Domnita Catalina Marinescu
Charge and spin density distributions are studied within a nanoring structure endowed with Rashba and Dresselhaus spin-orbit interactions (SOIs). For a small number of electrons, in the presence of an external magnetic field and of the Coulomb interaction, the energy spectrum of the system is calculated through an exact numerical diagonalization procedure. The eigenstates thus determined are used to estimate the charge and spin densities around the ring. We find that when more than two electrons are considered, the charge density deformations induced by SOIs are dramatically flattened by the Coulomb repulsion, while the spin density deformations are amplified.
Spin Mass Of An Electron Liquid, Zhixin Qian, Giovanni Vignale, D C. Marinescu
Spin Mass Of An Electron Liquid, Zhixin Qian, Giovanni Vignale, D C. Marinescu
Domnita Catalina Marinescu
We show that in order to calculate correctly the spin current carried by a quasiparticle in an electron liquid one must use an effective ‘‘spin mass’’ ms that is larger than both the band mass mb, which determines the charge current, and the quasiparticle effective mass m, which determines the heat capacity. We present two independent estimates of the spin mass enhancement, ms=mb, in two- and three-dimensional electron liquids, based on (i) previously calculated values of the Landau parameters and (ii) a recent theory of the dynamical local field factor in the spin channel. Both methods yield a significant spin …
Helical Antiferromagnetic Ordering In The Lowest Landau Level Of A Semiconductor Superlattice, Liqiu Zheng, D C. Marinescu
Helical Antiferromagnetic Ordering In The Lowest Landau Level Of A Semiconductor Superlattice, Liqiu Zheng, D C. Marinescu
Domnita Catalina Marinescu
When subjected to a tilted magnetic field, the ground state of a semiconductor superlattice (SL) with two identical quantum wells per unit cell is shown to exhibit different magnetic configurations that are dependent on the strength and direction of the field and the SL characteristics. Intra- and interunit cell tunneling between the wells, assumed to be infinitely attractive, generate an energy miniband structure of the lowest Landau level that, in cooperation with the Zeeman splitting, creates, at certain points in the momentum space, an energy difference between opposite-spin single-particle states that can be overcome by the Coulomb interaction. Within the …