Search results for "Hall"

Kondo Resonance in a Mesoscopic Ring Coupled to a Quantum Dot: Exact Results for the Aharonov-Bohm/Casher Effects

2000

We study the persistent currents induced by both the Aharonov-Bohm and Aharonov-Casher effects in a one-dimensional mesoscopic ring coupled to a side-branch quantum dot at Kondo resonance. For privileged values of the Aharonov-Bohm-Casher fluxes, the problem can be mapped onto an integrable model, exactly solvable by a Bethe ansatz. In the case of a pure magnetic Aharonov-Bohm flux, we find that the presence of the quantum dot has no effect on the persistent current. In contrast, the Kondo resonance interferes with the spin-dependent Aharonov-Casher effect to induce a current which, in the strong-coupling limit, is independent of the number of electrons in the ring.

Co-creation of Knowledge for Innovation Requires Multi-Stakeholder Public Relations

2018

Co-creation of knowledge requires intensive collaboration. Knowing the main challenges to address will help the functioning of co-creation collaboration networks and their public relations.

Discrete saturation thickness and anomalous potential height of native ultrathin aluminum oxide tunnel barriers

2001

We have investigated planar metal - insulator - metal tunnel junctions with aluminum oxide as dielectricum. These oxide barriers were grown on an aluminum electrode in pure oxygen at room temperature till saturation. We observed discrete barrier widths separated by \Delta s \approx 0.38 nm, corresponding to the addition of one layer of oxygen atoms. The minimum thickness of s_0 \approx 0.54 nm is due to a double layer of oxygen. We found a strong and systematic dependence of the barrier height \Phi_0 on the thickness s like \Phi_0 \approx 2.5 eV / s^2(nm), which nearly coincides with the kinetic electron energy E = h^2/2ms^2 for which the deBroglie wavelength matches the width of the barrie…

Electric voltage generation by antiferromagnetic dynamics

2015

We theoretically demonstrate dc and ac electric voltage generation due to spinmotive forces originating from domain wall motion and magnetic resonance, respectively, in two-sublattice antiferromagnets. Our theory accounts for the canting between the sublattice magnetizations, the nonadiabatic electron spin dynamics, and the Rashba spin-orbit coupling, with the inter-sublattice electron dynamics treated as a perturbation. This work suggests a new way to observe and explore the dynamics of antiferromagnetic textures by electrical means, an important aspect in the emerging field of antiferromagnetic spintronics, where both manipulation and detection of antiferromagnets are needed.

Rotating quantum liquids crystallize

2006

Small crystallites form when finite quantal systems are set highly rotating. This crystallization is independent of the statistics of the particles, and occurs for both trapped bosons and fermions. The spin degree of freedom does not change the tendency for localization. In a highly rotating state, the strongly correlated bosonic and fermionic systems approach to that of classical particles.

Persistent Currents in Small, Imperfect Hubbard Rings

2003

We have done a study with small, imperfect Hubbard rings with exact diagonalization. The results for few-electron rings show, that the imperfection, whether localized or not, nearly always decrease, but can also \emph{increase} the persistent current, depending on the character of the imperfection and the on-site interaction. The calculations are generally in agreement with more specialized studies. In most cases the electron spin plays an important role.

Effect of Static Disorder in an Electron-Fabry Perot Interferometr with Two Quantum Scattering Centers

2007

In a recent paper -- F. Ciccarello \emph{et al.}, New J. Phys. \textbf{8}, 214 (2006) -- we have demonstrated that the electron transmission properties of a one-dimensional (1D) wire with two identical embedded spin-1/2 impurities can be significantly affected by entanglement between the spins of the scattering centers. Such effect is of particular interest in the control of transmission of quantum information in nanostructures and can be used as a detection scheme of maximally entangled states of two localized spins. In this letter, we relax the constraint that the two magnetic impurities are equal and investigate how the main results presented in the above paper are affected by a static d…

Opettajaopiskelijan ammatti-identiteetti pedagogiikan, didaktiikan ja aineenhallinnan ammattilaisena

2015

TIIVISTELMÄ Karjalainen, Hanna. 2015. Opettajaopiskelijan ammatti-identiteetti pedagogiikan, didaktiikan ja aineenhallinnan ammattilaisena. Kasvatustieteen pro gradu -tutkielma. Jyväskylän yliopisto. Opettajankoulutuslaitos. Tutkimuksessa tarkastellaan luokanopettajiksi ja erityisopettajiksi opiskelevien ammatti-identiteettiä. Opettajan ammatti-identiteetin nähdään juontuvan siitä, miten hän arvottaa aineenhallintaa, pedagogiikkaa ja didaktiikkaa ammatissaan. Tutkimuksessa selvitetään, mitä opetuksen osa-aluetta opettajaopiskelijat pitävät ammatissaan tärkeimpänä: aineenhallintaa, pedagogiikkaa vai didaktiikkaa. Lisäksi tarkastellaan miten valitut tekijät, sukupuoli, opetuskokemus ja sivuai…

Sosialismin uusin verso : Unkarin kansannousun työläisneuvostot ja ajatus työläisten itsehallinnosta syksyllä 1956

2007

Weight Reduction Behaviors Among European Adolescents : Changes From 2001/2002 to 2017/2018

2020

Purpose The purpose of this study was to analyze changes in the prevalence of weight reduction behaviors (WRBs) among European adolescents from 26 countries between 2001/2002 and 2017/2018. The impact of the perception of body weight on WLB was also analyzed, with particular attention being paid to overestimation. Methods The data of 639,194 European adolescents aged 11, 13, and 15 years who participated in the Health Behaviour in School-aged Children survey were analyzed. Age-standardized prevalence rates of WRB were estimated separately by survey round and gender for each country, using the overall 2017/2018 Health Behaviour in School-aged Children study population as the standard. Multiv…