We determine the two-body contact in a planar Bose gas confined by a transverse harmonic potential, using the nonperturbative functional renormalization group. We use the three-dimensional thermodynamic definition of the contact where the latter is related to the derivation of the pressure of the quasi-two-dimensional system with respect to the three-dimensional scattering length of the bosons. Without any free parameter, we find a remarkable agreement with the experimental data of Zou et al.
View Article and Find Full Text PDFWe show that the Bose-glass phase of a one-dimensional disordered Bose fluid exhibits a chaotic behavior, i.e., an extreme sensitivity to external parameters.
View Article and Find Full Text PDFPhys Rev Lett
December 2020
We investigate the ground-state properties of quantum particles interacting via a long-range repulsive potential V_{σ}(x)∼1/|x|^{1+σ} (-1<σ) or V_{σ}(x)∼-|x|^{-1-σ} (-2≤σ<-1) that interpolates between the Coulomb potential V_{0}(x) and the linearly confining potential V_{-2}(x) of the Schwinger model. In the absence of disorder the ground state is a Wigner crystal when σ≤0. Using bosonization and the nonperturbative functional renormalization group we show that any amount of disorder suppresses the Wigner crystallization when -3/2<σ≤0; the ground state is then a Mott glass, i.
View Article and Find Full Text PDFWe study a one-dimensional disordered Bose fluid using bosonization, the replica method, and a nonperturbative functional renormalization-group approach. We find that the Bose-glass phase is described by a fully attractive strong-disorder fixed point characterized by a singular disorder correlator whose functional dependence assumes a cuspy form that is related to the existence of metastable states. At nonzero momentum scale k, quantum tunneling between the ground state and low-lying metastable states leads to a rounding of the cusp singularity into a quantum boundary layer (QBL).
View Article and Find Full Text PDFPhys Rev E
September 2019
We study a one-dimensional disordered Bose fluid using bosonization, the replica method, and a nonperturbative functional renormalization-group approach. The Bose-glass phase is described by a fully attractive strong-disorder fixed point characterized by a singular disorder correlator whose functional dependence assumes a cuspy form that is related to the existence of metastable states. At nonzero momentum scale, quantum tunneling between these metastable states leads to a rounding of the nonanalyticity in a quantum boundary layer that encodes the existence of rare superfluid regions responsible for the ω^{2} behavior of the (dissipative) conductivity in the low-frequency limit.
View Article and Find Full Text PDFWe present a Mach-Zehnder-based optical switch with novel electrooptic shift-and-dump phase shifters that have no residual amplitude modulation. As a result, the switch can have a very high extinction ratio with no overhead in power dissipation or insertion loss compared to standard electrooptic Mach-Zehnder switches. We fabricate the switch in an all-digital silicon photonic platform that monolithically integrates the actuation and control electronics together with the photonics.
View Article and Find Full Text PDFWe present an all-digital, fully programmable, nanosecond-scale photonic switch platform, monolithically integrating electronics for actuation, tuning, and power-monitoring alongside switching elements, resulting in a scalable, packageable solution for high-radix photonic switch fabrics. In this platform, we achieve record loss and extinction performances utilizing a 2×2 Mach-Zehnder switch (MZS) with 0.8 dB of loss and 28 dB extinction and a 2×2 nested MZS with 1.
View Article and Find Full Text PDFPurpose: To assess whether virtual non-contrast (VNC) images derived from contrast dual-layer dual-energy computed tomography (DL-DECT) images could replace true non-contrast (TNC) images for aortic intramural hematoma (IMH) diagnosis in acute aortic syndrome (AAS) imaging protocols by performing quantitative as well as qualitative phantom and clinical studies.
Materials And Methods: Patients with confirmed IMH were included retrospectively in two centers. For in vitro imaging, a custom-made phantom of IMH was placed in a semi-anthropomorphic thorax phantom (QRM GmbH) and imaged on a DL-DECT at 120 kVp under various conditions of patient size, radiation exposure, and reconstruction modes.
We present the design and characterization of a novel electro-optic silicon photonic 2×2 nested Mach-Zehnder switch monolithically integrated with a CMOS driver and interface logic. The photonic device uses a variable optical attenuator in order to balance the power inside the Mach-Zehnder interferometer leading to ultralow crosstalk performance. We measured a crosstalk as low as -34.
View Article and Find Full Text PDFGrating couplers are proposed for polarization-independent coupling of light between a single-mode fiber and a 220-nm-thick channel waveguide on silicon-on-insulator. The grating couplers have nonuniform grating periods that are composed of the intersection or union of a set of two near-optimal TE- and TM-grating periods. The proposed grating couplers have a coupling efficiency greater than 20% and polarization dependent loss (PDL) lower than 0.
View Article and Find Full Text PDFWe propose and demonstrate an integrated optical isolator in InP using two phase modulators in series. The phase modulators are driven with a single-frequency signal in quadrature. Theoretically there is no effect on the forward signal, and the carrier of the backward signal can be eliminated, the energy distributed to other frequencies.
View Article and Find Full Text PDFBased on previous evidence suggesting positive effects of fever on in vivo hematopoiesis, we tested the effect of hyperthermia on megakaryopoiesis (MK) in ex vivo cultures of CD34-enriched cord blood (CB) cells. The cells were cultured at 37 degrees C or 39 degrees C for 14 days in cytokine conditions optimized for megakaryocyte development and analyzed periodically. Compared to 37 degrees C, the cultures maintained at 39 degrees C produced significantly more (up to 10-fold) total cells, myeloid and MK progenitors, and total MKs, and showed accelerated and enhanced MK maturation with increased yields of proplatelets and platelets.
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