Programmable time-multiplexed squeezed light source

One of the leading approaches to large-scale quantum information processing (QIP) is the continuous-variable (CV) scheme based on time multiplexing (TM). As a fundamental building block for this approach, quantum light sources to sequentially produce time-multiplexed squeezed-light pulses are required; however, conventional CV TM experiments have used fixed light sources that can only output the squeezed pulses with the same squeezing levels and phases. We here demonstrate a programmable time-multiplexed squeezed light source that can generate sequential squeezed pulses with various squeezing levels and phases at a time interval below 100 ns. The generation pattern can be arbitrarily chosen by software without changing its hardware configuration. This is enabled by using a waveguide optical parametric amplifier and modulating its continuous pump light. Our light source will implement various large-scale CV QIP tasks.Comment: 14 pages, 7 figure

International retrospective study of allogeneic hematopoietic cell transplantation for activated PI3K-delta syndrome

Immunodeficiència primària; Limfoproliferació; Inhibidor de mTORInmunodeficiencia primaria; Linfoproliferación; Inhibidor de mTORPrimary immunodeficiency; Lymphoproliferation; MTOR inhibitorBackground Activated phosphoinositide 3-kinase delta syndrome (APDS) is a combined immunodeficiency with a heterogeneous phenotype considered reversible by allogeneic hematopoietic cell transplantation (HCT). Objectives This study sought to characterize HCT outcomes in APDS. Methods Retrospective data were collected on 57 patients with APDS1/2 (median age, 13 years; range, 2-66 years) who underwent HCT. Results Pre-HCT comorbidities such as lung, gastrointestinal, and liver pathology were common, with hematologic malignancy in 26%. With median follow-up of 2.3 years, 2-year overall and graft failure–free survival probabilities were 86% and 68%, respectively, and did not differ significantly by APDS1 versus APDS2, donor type, or conditioning intensity. The 2-year cumulative incidence of graft failure following first HCT was 17% overall but 42% if mammalian target of rapamycin inhibitor(s) (mTORi) were used in the first year post-HCT, compared with 9% without mTORi. Similarly, 2-year cumulative incidence of unplanned donor cell infusion was overall 28%, but 65% in the context of mTORi receipt and 23% without. Phenotype reversal occurred in 96% of evaluable patients, of whom 17% had mixed chimerism. Vulnerability to renal complications continued post-HCT, adding new insights into potential nonimmunologic roles of phosphoinositide 3-kinase not correctable through HCT. Conclusions Graft failure, graft instability, and poor graft function requiring unplanned donor cell infusion were major barriers to successful HCT. Post-HCT mTORi use may confer an advantage to residual host cells, promoting graft instability. Longer-term post-HCT follow-up of more patients is needed to elucidate the kinetics of immune reconstitution and donor chimerism, establish approaches that reduce graft instability, and assess the completeness of phenotype reversal over time.This research was funded in part from the Intramural Program of the National Cancer Institute, National Institutes of Health. The funding source had no involvement in study design; collection, analysis, and interpretation of data; writing of the report; or in the decision to submit the article for publication

Ab initio study of ferroelectricity in edged PbTiO3 nanowires under axial tension

The atomistic and electronic structures of PbTiO3 nanowires with characteristic edges consisting of (100) and (010) surfaces and the crucial role of axial tensile strain on ferroelectricity have been investigated by means of ab initio density-functional theory calculations. Ferroelectricity is enhanced at the edge of the PbO-terminated nanowire because the Pb-O covalent bond that predominates ferroelectric distortions is locally strengthened. On the other hand, a considerable suppression is found in the TiO2-terminated nanowire, caused by the charge transfer from the Pb-O site to the Ti-O site. Surprisingly, the smallest PbO-terminated nanowire with a cross section of only one-unit cell can possess ferroelectricity while ferroelectricity disappears in the TiO2-terminated nanowires with a cross section smaller than four-by-four cells (diameter of about 17 Å). However, ferroelectricity is recovered by axial tension, where smaller nanowires require larger critical strains