Phase-Driving Hole Spin Qubits.

The spin-orbit interaction in spin qubits enables spin-flip transitions, resulting in Rabi oscillations when an external microwave field is resonant with the qubit frequency. Here, we introduce an alternative driving mechanism mediated by the strong spin-orbit interactions in hole spin qubits, where a far-detuned oscillating field couples to the qubit phase. Phase-driving at radio frequencies, orders of magnitude slower than the microwave qubit frequency, induces highly nontrivial spin dynamics, violating the Rabi resonance condition.

Edge-State Wave Functions from Momentum-Conserving Tunneling Spectroscopy.

We perform momentum-conserving tunneling spectroscopy using a GaAs cleaved-edge overgrowth quantum wire to investigate adjacent quantum Hall edge states. We use the lowest five wire modes with their distinct wave functions to probe each edge state and apply magnetic fields to modify the wave functions and their overlap. This reveals an intricate and rich tunneling conductance fan structure which is succinctly different for each of the wire modes.

Closed-Form Weak Localization Magnetoconductivity in Quantum Wells with Arbitrary Rashba and Dresselhaus Spin-Orbit Interactions.

We derive a closed-form expression for the weak localization (WL) corrections to the magnetoconductivity of a 2D electron system with arbitrary Rashba α and Dresselhaus β (linear) and β_{3} (cubic) spin-orbit interaction couplings, in a perpendicular magnetic field geometry. In a system of reference with an in-plane z[over ^] axis chosen as the high spin-symmetry direction at α=β, we formulate a new algorithm to calculate the three independent contributions that lead to WL. The antilocalization is counterbalanced by the term associated with the spin relaxation along z[over ^], dependent only on α-β.

Blurring the Boundaries Between Topological and Nontopological Phenomena in Dots.

We investigate the electronic and transport properties of topological and nontopological InAs_{0.85}Bi_{0.15} quantum dots (QDs) described by a ∼30  meV gapped Bernevig-Hughes-Zhang (BHZ) model with cylindrical confinement, i.

Persistent Skyrmion Lattice of Noninteracting Electrons with Spin-Orbit Coupling.

A persistent spin helix (PSH) is a robust helical spin-density pattern arising in disordered 2D electron gases with Rashba α and Dresselhaus β spin-orbit (SO) tuned couplings, i.e., α=±β.

Many-body effects on the rho(xx) ringlike structures in two-subband wells.

The longitudinal resistivity rho(xx) of two-dimensional electron gases formed in wells with two subbands displays ringlike structures when plotted in a density-magnetic-field diagram, due to the crossings of spin-split Landau levels (LLs) from distinct subbands. Using spin density functional theory and linear response, we investigate the shape and spin polarization of these structures as a function of temperature and magnetic-field tilt angle. We find that (i) some of the rings "break" at sufficiently low temperatures due to a quantum Hall ferromagnetic phase transition, thus exhibiting a high degree of spin polarization (approximately 50%) within, consistent with the NMR data of Zhang et al.

Epidemiological and clinical analysis of a consecutive series of conjoined twins in Spain.

Purpose: The aim of the study was to analyze the frequency and certain epidemiological characteristics of a consecutive series of conjoined twins born in Spain.

Material And Methods: We used data from the Spanish Collaborative Study of Congenital Malformations for the period April 1976 to 2006. Because the Spanish law permitting voluntary termination of pregnancies (TOP) when the fetus presented malformations was effective by the end of 1985, we analyzed the data in 4 periods, 2 before 1986 and 2 after.

Spin-orbit interaction in symmetric wells with two subbands.

We investigate the spin-orbit (SO) interaction in two-dimensional electron gases in quantum wells with two subbands. From the 8x8 Kane model, we derive a new intersubband-induced SO term which resembles the functional form of the Rashba SO but is nonzero even in symmetric structures. This follows from the distinct parity of the confined states (even or odd) which obliterates the need for asymmetric potentials.

Hysteretic resistance spikes in quantum hall ferromagnets without domains.

We use spin-density-functional theory to study recently reported hysteretic magnetoresistance rho(xx) spikes in Mn-based 2D electron gases [Phys. Rev. Lett.

Nonballistic spin-field-effect transistor.

We propose a spin-field-effect transistor based on spin-orbit coupling of both the Rashba and the Dresselhaus types. Different from earlier proposals, spin transport through our device is tolerant against spin-independent scattering processes. Hence the requirement of strictly ballistic transport can be relaxed.

Rashba spin-orbit interaction and shot noise for spin-polarized and entangled electrons.

We study shot noise for spin-polarized currents and entangled electron pairs in a four-probe (beam-splitter) geometry with a local Rashba spin-orbit (s-o) interaction in the incoming leads. Within the scattering formalism we find that shot noise exhibits Rashba-induced oscillations with continuous bunching and antibunching. We show that entangled states and triplet states can be identified via their Rashba phase in noise measurements.

[Children with limb reductions in a population of 25,193 malformed newborns: the recognized causes. ECEMC. The Spanish Collaborative Study of Congenital Malformations].

Objective: The purposes of this study were to analyze the causes of limb reduction deficiencies based on a clinical-epidemiological approach and to study the causes by clinical presentation.

Patients And Methods: We have used the data from the Spanish Collaborative Study of Congenital Malformations (ECEMC) during the period from 1976 to 1996, which corresponded to more than 1,300,000 births. Among these, we identified 851 liver-born and 40 stillborn infants with limb reduction defects.

Primary midline developmental field. II. Clinical/epidemiological analysis of alteration of laterality (normal body symmetry and asymmetry).

Lubinsky [Am J Med Genet 3:23-28, 1987] has suggested that the properties of the midline involve early determinative informational processes and are related to the midline's position and definition of the body's plane of symmetry. Opitz [Am J Med Genet 21:175-176, 1985, BD: OAS XXIX(1):3-37 1993] has pointed out that the laterality sequences represent a midline developmental field complex. Thus, bilateral left-sidedness (with asplenia) and bilateral right-sidedness (with asplenia) have been considered laterality sequences or syndromes if cause is known.

Severe spondylocostal dysostosis associated with other congenital anomalies: a clinical/epidemiologic analysis and description of ten cases from the Spanish registry.

We describe 10 cases born to nondiabetic mothers who presented with severe spondylocostal dysostosis (SCD) associated with other anomalies, identified among 20,526 malformed liveborn infants from the Spanish Collaborative Study of Congenital Malformations (ECEMC). We analyze the associated malformations in the 10 cases with severe SCD, as well as in all cases with less severe SCD among children with MCA patterns of unknown cause. Cases with SCD were preferentially associated with caudal dysgenesis, diaphragmatic hernia, and central nervous system anomalies.

Short rib-polydactyly syndrome (SRPS) with anencephaly and other central nervous system anomalies: a new type of SRPS or a more severe expression of a known SRPS entity?

We describe two patients with short rib-polydactyly syndrome (SRPS) from two unrelated Spanish families. These patients present clinical and radiological characteristics that overlap those of the different established types of SRPS. In addition, one patient had anencephaly and the other patient had severe brain abnormalities with a family history of an older sister with anencephaly, and a brother diagnosed with SRPS.

[Trisomy 9p. Apropos of 2 cases].

Two cases of trisomy 9p are presented. The different cytogenetic mechanism given in these cases shows us that with independence of it, it exists a triplication of the half distal short arm of chromosome 9 which gives specificity to these phenotypic features. It might be a possible meiotic origin of the chromosomic rearrangement on both translocations, the formation of satellited chromosomes and isochromosomes of the short arm on chromosome 9 and the consequently wrong segregation of each one of them.

[Camptomelic dysplasia associated with true hermaphroditism].

Authors present a new case of campomelic dysplasia associated to true hermaphroditism. Clinical and radiological findings are described. Ethiopatogenical factors are widely discussed, and special correlation between campomelic dysplasia and sexual reverse, is noted, according to new concepts on H-Y antigen.

[Myocardial infarction in relation to perinatal hypoxia].

Six newborn infants with myocardial infarction are presented. All of them had a history of perinatal hypoxemia and their natal weights were below 2,500 g. All infants developed cardiogenic "shock" during and required assisted ventilation.

[Short rib-polydactyly (author's transl)].

A new case of short rib-polydoctyly, Saldino-Noonan type is described. The authors make a differential diagnosis between another forms of neonatal chondrodysplasias and point-out principal features of this entity.