Electrical Tuning of Single Nitrogen-Vacancy Center Optical Transitions Enhanced by Photoinduced Fields

We demonstrate precise control over the zero-phonon optical transition energies of individual nitrogen-vacancy (NV) centers in diamond by applying multiaxis electric fields, via the dc Stark effect. The Stark shifts display surprising asymmetries that we attribute to an enhancement and rectification of the local electric field by photoionized charge traps in the diamond. Using this effect, we tune the excited-state orbitals of strained NV centers to degeneracy and vary the resulting degenerate optical transition frequency by >10 GHz, a scale comparable to the inhomogeneous frequency distribution. This technique will facilitate the integration of NV-center spins within photonic networks.Comment: 10 pages, 6 figure

Thermoelectricity in Nanowires: A Generic Model

By employing a Boltzmann transport equation and using an energy and size dependent relaxation time ($\tau$) approximation (RTA), we evaluate self-consistently the thermoelectric figure-of-merit $ZT$ of a quantum wire with rectangular cross-section. The inferred $ZT$ shows abrupt enhancement in comparison to its counterparts in bulk systems. Still, the estimated $ZT$ for the representative Bi$_2$Te$_3$ nanowires and its dependence on wire parameters deviate considerably from those predicted by the existing RTA models with a constant $\tau$. In addition, we address contribution of the higher energy subbands to the transport phenomena, the effect of chemical potential tuning on $ZT$, and correlation of $ZT$ with quantum size effects (QSEs). The obtained results are of general validity for a wide class of systems and may prove useful in the ongoing development of the modern thermoelectric applications.Comment: 15 pages, 6 figures; Dedicated to the memory of Amirkhan Qezell

Atomic layer deposition of titanium nitride for quantum circuits

Superconducting thin films with high intrinsic kinetic inductance are of great importance for photon detectors, achieving strong coupling in hybrid systems, and protected qubits. We report on the performance of titanium nitride resonators, patterned on thin films (9-110 nm) grown by atomic layer deposition, with sheet inductances of up to 234 pH/square. For films thicker than 14 nm, quality factors measured in the quantum regime range from 0.4 to 1.0 million and are likely limited by dielectric two-level systems. Additionally, we show characteristic impedances up to 28 kOhm, with no significant degradation of the internal quality factor as the impedance increases. These high impedances correspond to an increased single photon coupling strength of 24 times compared to a 50 Ohm resonator, transformative for hybrid quantum systems and quantum sensing.Comment: 10 pages, 8 figures including supplemental material

ASSOCIATION OF LACTOFERRIN WITH SPECIFIC GRANULES IN RABBIT HETEROPHIL LEUKOCYTES

Lactoferrin has been identified in rabbit heterophil leukocytes on the basis of its immunological reactivity, electrophoretic mobility, acid-resistant iron-binding properties, and spectral characteristics. Leukocyte lactoferrin was found to be exclusively localized in the specific (secondary) granules, which have been resolved from other subcellular components by zonal differential centrifugation and by isopycnic equilibration

ANTIBODIES OF THE IgA TYPE IN INTESTINAL PLASMA CELLS OF GERMFREE MICE AFTER ORAL OR PARENTERAL IMMUNIZATION WITH FERRITIN

In adult germfree C3H mice immunized with horse spleen ferritin, either subcutaneously or intraperitoneally, plasma cells containing specific antibodies were found in lymph nodes and spleen and, in smaller numbers, also in the lamina propria of the intestine. In extraintestinal sites, these antiferritin-containing plasma cells were mainly of the IgM class after a single stimulation, and of the IgG1 class after repeated stimulation. In the intestine, all the anti-ferritin-containing cells appeared to be of the IgA class. Circulating antibodies, after repeated stimulation, were for the major part IgG1 and IgG2. In germfree mice given ferritin in their drinking water, antiferritin-containing cells were abundant in the intestinal mucosa, much less numerous in the mesenteric lymph nodes, and extremely scarce in other lymphoid tissues. All these cells, whatever their location, appeared to belong exclusively to the IgA class. Similarly, all the circulating antibody in these animals was found to be IgA. These findings illustrate the role of the gut as a site of antibody synthesis, as well as its selective commitment to the production of antibodies of the IgA class