We show that density-dependent synthetic gauge fields may be engineered by combining periodically modulated interactions and Raman-assisted hopping in spin-dependent optical lattices. These fields ...lead to a density-dependent shift of the momentum distribution, may induce superfluid-to-Mott insulator transitions, and strongly modify correlations in the superfluid regime. We show that the interplay between the created gauge field and the broken sublattice symmetry results, as well, in an intriguing behavior at vanishing interactions, characterized by the appearance of a fractional Mott insulator.
When a periodically modulated many-body quantum system is weakly coupled to an environment, the combined action of these temporal modulations and dissipation steers the system towards a state ...characterized by a time-periodic density operator. To resolve this asymptotic non-equilibrium state at stroboscopic instants of time, we use the dissipative propagator over one period of modulations, 'Floquet map', and evaluate the stroboscopic density operator as its invariant. Particle interactions control properties of the map and thus the features of its invariant. In addition, the spectrum of the map provides insight into the system relaxation towards the asymptotic state and may help to understand whether it is possible (or not) to construct a stroboscopic time-independent Lindblad generator which mimics the action of the original time-dependent one. We illustrate the idea with a scalable many-body model, a periodically modulated Bose-Hubbard dimer. We contrast the relations between the interaction-induced bifurcations in a mean-field description with the numerically exact stroboscopic evolution and discuss the characteristics of the genuine quantum many-body state vs the characteristics of its mean-field counterpart.
We present a protocol to selectively decouple, recouple, and engineer effective interactions in mesoscopic dipolar spin networks. In particular, we develop a versatile protocol that relies upon magic ...angle spinning to perform Hamiltonian engineering. By using global control fields in conjunction with a local actuator, such as a diamond nitrogen vacancy center located in the vicinity of a nuclear spin network, both global and local control over the effective couplings can be achieved. We show that the resulting effective Hamiltonian can be well understood within a simple, intuitive geometric picture, and corroborate its validity by performing exact numerical simulations in few-body systems. Applications of our method are in the emerging fields of two-dimensional room temperature quantum simulators in diamond platforms, as well as in molecular magnet systems.
We report a measurement of the E-mode polarization power spectrum of the cosmic microwave background (CMB) using 150 GHz data taken from 2014 July to 2016 December with the Polarbear experiment. We ...reach an effective polarization map noise level of - across an observation area of 670 square degrees. We measure the EE power spectrum over the angular multipole range , tracing the third to seventh acoustic peaks with high sensitivity. The statistical uncertainty on E-mode bandpowers is ∼2.3 at , with a systematic uncertainty of 0.5 . The data are consistent with the standard ΛCDM cosmological model with a probability-to-exceed of 0.38. We combine recent CMB E-mode measurements and make inferences about cosmological parameters in ΛCDM as well as in extensions to ΛCDM. Adding the ground-based CMB polarization measurements to the Planck data set reduces the uncertainty on the Hubble constant by a factor of 1.2 to . When allowing the number of relativistic species ( ) to vary, we find , which is in good agreement with the standard value of 3.046. Instead allowing the primordial helium abundance ( ) to vary, the data favor . This is very close to the expectation of 0.2467 from big bang nucleosynthesis. When varying both and , we find and .
We present a measurement of the gravitational lensing deflection power spectrum reconstructed with two seasons of cosmic microwave background polarization data from the Polarbear experiment. ...Observations were taken at 150 GHz from 2012 to 2014 and surveyed three patches of sky totaling 30 square degrees. We test the consistency of the lensing spectrum with a cold dark matter cosmology and reject the no-lensing hypothesis at a confidence of 10.9 , including statistical and systematic uncertainties. We observe a value of AL = 1.33 0.32 (statistical) 0.02 (systematic) 0.07 (foreground) using all polarization lensing estimators, which corresponds to a 24% accurate measurement of the lensing amplitude. Compared to the analysis of the first-year data, we have improved the breadth of both the suite of null tests and the error terms included in the estimation of systematic contamination.
Background
Asthma and other Th2 inflammatory conditions have been associated with increased susceptibility to viral infections. The mechanisms by which Th2 cytokines can influence immune responses to ...infections are largely unknown.
Methods
We measured the effects of Th2 cytokines (IL‐4 and IL‐13) on bronchial epithelial cell innate immune antiviral responses by assessing interferon (IFN‐β and IFN‐λ1) induction following rhinovirus (RV)‐16 infection. We also investigated the modulatory effects of Th2 cytokines on Toll‐like receptor 3 (TLR3), interferon‐responsive factor 3 (IRF3) and nuclear factor (NF)‐kB, that is key molecules and transcription factors involved in the rhinovirus‐induced interferon production and inflammatory cascade. Pharmacological and redox modulation of these pathways was also assessed.
Results
Th2 cytokines impaired RV‐16‐induced interferon production, increased rhinovirus replication and impaired TLR3 expression in bronchial epithelial cells. These results were replicated in vivo: we found increased IL‐4 mRNA levels in nasal epithelial cells from nasal brushing of atopic rhinitis patients and a parallel reduction in TLR3 expression and increased RV‐16 replication compared to nonatopic subjects. Mechanistically, Th2 cytokines impaired RV‐16‐induced activation of IRF3, but had no effects on RV‐16‐induced NF‐kB activation in bronchial epithelial cell cultures. N‐acetylcysteine and phosphoinositide 3‐kinase (PI3K) inhibitor restored the inhibitory effects of Th2 cytokines over RV‐16‐induced activation of IRF3.
Conclusions
IL‐4 and IL‐13, through inhibition of TLR3 expression and signalling (IRF3), impair immune response to RV‐16 infection. These data suggest that Th2 conditions increase susceptibility to infections and identify pharmacological approaches with potential to restore impaired immune response in these conditions.
We report an improved measurement of the cosmic microwave background B-mode polarization power spectrum with the Polarbear experiment at 150 GHz. By adding new data collected during the second season ...of observations (2013-2014) to re-analyzed data from the first season (2012-2013), we have reduced twofold the band-power uncertainties. The band powers are reported over angular multipoles , where the dominant B-mode signal is expected to be due to the gravitational lensing of E-modes. We reject the null hypothesis of no B-mode polarization at a confidence of 3.1 including both statistical and systematic uncertainties. We test the consistency of the measured B-modes with the Λ Cold Dark Matter (ΛCDM) framework by fitting for a single lensing amplitude parameter AL relative to the Planck 2015 best-fit model prediction. We obtain 0.14(foreground) 0.04(multi), where is the fiducial ΛCDM value.
We present a measurement of the B-mode polarization power spectrum of the cosmic microwave background (CMB) using data taken from 2014 July to 2016 December with the Polarbear experiment. The CMB ...power spectra are measured using observations at 150 GHz with an instantaneous array sensitivity of on a 670 square degree patch of sky centered at (R.A., decl.) = (+0h12m0s, −59°18′). A continuously rotating half-wave plate is used to modulate polarization and to suppress low-frequency noise. We achieve 32 K arcmin effective polarization map noise with a knee in sensitivity of = 90, where the inflationary gravitational-wave signal is expected to peak. The measured B-mode power spectrum is consistent with a ΛCDM lensing and single dust component foreground model over a range of multipoles 50 ≤ ≤ 600. The data disfavor zero at 2.2 using this range of Polarbear data alone. We cross-correlate our data with Planck full mission 143, 217, and 353 GHz frequency maps and find the low- B-mode power in the combined data set to be consistent with thermal dust emission. We place an upper limit on the tensor-to-scalar ratio r < 0.90 at the 95% confidence level after marginalizing over foregrounds.
PDF
