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Showing 1 to 14 of 14 for “"Spin gap"”.
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Spin Properties of Heavy Holes in Low-Dimensional Quantum Electronic Devices
The rich spin physics in quantum confined holes has attracted significant ongoing research interest for over 20 years. The ability to manipulate the spin degrees of freedom in spin-orbit coupled holes via an electric field has opened up the field of spin-based electronics, or spintronics. In this …
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Bandstructure calculations for holes in GaAs and simulations of dc conductance in electron quantum point contacts
… explicitly include Rashba and Dresselhaus spin-orbit terms. The effective mass of the holes at the zone center is calculated. The calculations show that the Rashba and Dresselhaus terms change the hole bandstructure and should not be ignored. We looked at the accuracy of different methods …
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The ground state of the spin-1/2 kagomé lattice antiferromagnet : neutron scattering studies of the zinc-paratacamite mineral family
… the nature of the ground state of the spin-1 2 kagomé lattice antiferromagnet, as such a system is considered ideal for the emergence of spin liquid physics. Clinoatacamite, a distorted kagomé lattice antiferromagnet with weak inter-plane coupling, undergoes a Néel or- dering transition …
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Aspects of spin-charge separation in high Tc cuprates
… resistivity in optimally doped cuprates, the "spin gap" phenomena, and antiferromagnetic fluctuations. Some of the basic features of the high Tc, phase diagram can be readily understood from slave boson mean field theories of the t-J model that yield a variety of phases like the uRVB phase …
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Neutron scattering and magnetization studies of the spin correlations on the kagomé lattice antiferromagnet KFe₃(Oh)₆(SO₄)₂
… the 2D Ising transition. Above TN, the in-plane spin gap vanishes, and the system retains the SO(2) symmetry when measured with neutron scattering. On the other hand, specific heat measurements show a feature of the 2D Ising transition, since the underlying symmetry of the spin Hamiltonian is the …
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Magnetic-field-induced antiferromagnetism in the Kondo lattice
… energy comparable to the Kondo energy, the spin gap closes and the system develops transverse staggered magnetic order. The charge gap, however, remains robust up to a higher hybridization energy scale, at which point the canted antiferromagnetism is exponentially suppressed and the system …
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Terahertz spectroscopy of quantum spin liquids
The optical properties of the spin-1/2 kagome lattice antiferromagnetic Herbertsmithite, ZnCu₃(OH)₆Cl₂, are studied by means of Terahertz Time-Domain Spectroscopy. Herbertsmithite is proposed to exhibit Quantum Spin Liquid behavior, in which electron spins have strong antiferromagnetic …
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Computational Studies of Correlated Electrons in One-Dimension
… construction of ""operator-loop"" updates for spin-1/2 fermions and the inclusion of electron-phonon interactions in the Stochastic Series Expansion Quantum Monte Carlo method and the use of Quantum Parallel Tempering to improve the quality of the numerical data. For the extended Hubbard model …
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23Na/51 V-NMR study of (Alpha)´- NaV2O5
… is reported and discussed. The measurements of spin-lattice relaxation for 23Na and 51V are also presented. The sodium vanadate is found to have a double phase transition. The two transitions are close together and take place around 34 K. Above the transition temperature there is one V site in …
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Synthesis, structure, and magnetic properties of spin-1/2 kagomé antiferromagnets
… a kagomé because they exhibit strong geometric spin frustration and are predicted to show no magnetic long-range ordering (LRO). The three broad classes of kagomé layered materials presented herein--covalently linked layers, hydrogen-bonded layers, and electrostatically linked layers--reflect …
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Coupled one dimensional electron systems and stripe phases of high temperature superconductors
… the problem of the Local Density of States for spin-gapped one-dimensional charge density wave (CDW) states and Mott insulators in the presence of a hard-wall boundary. I calculate the boundary contribution to the single-particle Green function in the low-energy limit using field theory …
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Using multiplexers to study the statistics of quantum phenomenon in one-dimensional wires
… $g^*$, which could be beneficial for its use in spintronic applications. Last, we investigate the formation and development of the DC-bias-induced 0.75 and 0.25 anomalies for 402 QPCs. We find the anomalies evolve similarly in a magnetic field. To explain the anomaly behaviours, we propose a …
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Field theoretical methods for strongly correlated electron systems
… Quantum Antiferromagnet. We study the Chiral Spin Liquid state of the antiferromagnet at zerotemperature, which has a spin-gap generated by the spontaneous breakdown of time-reversalsymmetry. This state is known as the Chiral Spin State. We determine conditions for the restoration of …
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Geometric frustration in high spin orbit coupling magnetic materials
… of frustrated materials. The ferrimagnetic spinel $\mathrm{CoV_2O_4}$ has been a topic of recent interest, both as a frustrated insulator with unquenched orbital degeneracy and as a near-itinerant magnet which can be driven metallic with moderate applied pressure. Here, we report on our …