Spin-½

About: Spin-½ is a research topic. Over the lifetime, 40423 publications have been published within this topic receiving 796639 citations.

Experimental evidence for the Haldane gap in a spin-1 nearly isotropic, antiferromagnetic chain.

Abstract: Neutron scattering has shown that the lowest spin excitations in the spin-1 antiferromagnet ${\mathrm{CsNiCl}}_{3}$ in its one-dimensional phase occur at finite frequency. After allowance for the known weak interchain coupling the gap is found to be in good agreement with recent numerical calculations. The results support the Haldane conjecture that in integral-spin chains with isotropic interactions a gap separates the ground state from the excitations.

Matrix Product Ground States for One-Dimensional Spin-1 Quantum Antiferromagnets

Abstract: We have found the exact ground state for a large class of antiferromagnetic spin-1 models with nearest-neighbour interactions on a linear chain. All ground-state properties can be calculated. The ground state is determined as a matrix product of individual site states and has the properties of the Haldane scenario.

Double Field Theory of Type II Strings

Abstract: We use double field theory to give a unified description of the low energy limits of type IIA and type IIB superstrings. The Ramond-Ramond potentials fit into spinor representations of the duality group O(D, D) and field-strengths are obtained by acting with the Dirac operator on the potentials. The action, supplemented by a Spin+ (D, D)-covariant self-duality condition on field strengths, reduces to the IIA and IIB theories in different frames. As usual, the NS-NS gravitational variables are described through the generalized metric. Our work suggests that the fundamental gravitational variable is a hermitian element of the group Spin(D, D) whose natural projection to O(D, D) gives the generalized metric.

Spin decoherence of a heavy hole coupled to nuclear spins in a quantum dot

Abstract: We theoretically study the interaction of a heavy hole with nuclear spins in a quasi-two-dimensional III--V semiconductor quantum dot and the resulting dephasing of heavy-hole spin states. It has frequently been stated in the literature that heavy holes have a negligible interaction with nuclear spins. We show that this is not the case. In contrast, the interaction can be rather strong and will be the dominant source of decoherence in some cases. We also show that for unstrained quantum dots the form of the interaction is Ising, resulting in unique and interesting decoherence properties, which might provide a crucial advantage to using dot-confined hole spins for quantum information processing, as compared to electron spins.