Heralded state preparation in a superconducting qubit

We demonstrate high-fidelity, quantum nondemolition, single-shot readout of a superconducting flux qubit in which the pointer state distributions can be resolved to below one part in 1000. In the weak excitation regime, continuous measurement permits the use of heralding to ensure initialization to a fiducial state, such as the ground state. This procedure boosts readout fidelity to 93.9% by suppressing errors due to spurious thermal population. Furthermore, heralding potentially enables a simple, fast qubit reset protocol without changing the system parameters to induce Purcell relaxation.Comment: 5 pages, 5 figure

Phylogenetic signal in phonotactics

Phylogenetic methods have broad potential in linguistics beyond tree inference. Here, we show how a phylogenetic approach opens the possibility of gaining historical insights from entirely new kinds of linguistic data – in this instance, statistical phonotactics. We extract phonotactic data from 112 Pama-Nyungan vocabularies and apply tests for phylogenetic signal, quantifying the degree to which the data reflect phylogenetic history. We test three datasets: (1) binary variables recording the presence or absence of biphones (two-segment sequences) in a lexicon (2) frequencies of transitions between segments, and (3) frequencies of transitions between natural sound classes. Australian languages have been characterized as having a high degree of phonotactic homogeneity. Nevertheless, we detect phylogenetic signal in all datasets. Phylogenetic signal is greater in finer-grained frequency data than in binary data, and greatest in natural-class-based data. These results demonstrate the viability of employing a new source of readily extractable data in historical and comparative linguistics.1. Introduction 1.1 Motivations 1.2 Phonotactics as a source of historical signal 2. Phylogenetic signal 3. Materials 3.1 Language sample 3.2 Wordlists 3.3 Reference phylogeny 4. Phylogenetic signal in binary phonotactic data 4.1 Results for binary phonotactic data 4.2 Robustness checks 5. Phylogenetic signal in continuous phonotactic data 5.1 Robustness checks 5.2 Forward transitions versus backward transitions 5.3 Normalization of character values 6. Phylogenetic signal in natural-class-based characters 6.1 Natural-class-based characters versus biphones 7. Discussion 7.1 Overall robustness 7.2 Limitations 8. Conclusio

Hypervelocity impact survivability experiments for carbonaceous impactors

We performed a series of hypervelocity impact experiments using carbon-bearing impactors (diamond, graphite, fullerenes, phthalic acid crystals, and Murchison meteorite) into Al plate at velocities between 4.2 and 6.1 km/s. These tests were made to do the following: (1) determine the survivability of carbon forms and organize molecules in low hypervelocity impact; (2) characterize carbonaceous impactor residues; and (3) determine whether or not fullerenes could form from carbonaceous impactors, under our experimental conditions, or survive as impactors. An analytical protocol of field emission SEM imagery, SEM-EDX, laser Raman spectroscopy, single and 2-stage laser mass spectrometry, and laser induced fluorescence (LIF) found the following: (1) diamonds did not survive impact at 4.8 km/s, but were transformed into various forms of disordered graphite; (2) intact, well-ordered graphite impactors did survive impact at 5.9 km/sec, but were only found in the crater bottom centers; the degree of impact-induced disorder in the graphite increases outward (walls, rims, ejecta); (3) phthalic acid crystals were destroyed on impact (at 4.2 km/s, although a large proportion of phthalic acid molecules did survive impact); (4) fullerenes did not form as products of carbonaceous impactors (5.9 - 6.1 km/s, fullerene impactor molecules mostly survived impact at 5.9 km/s; and (5) two Murchison meteorite samples (launched at 4.8 and 5.9 km/s) show preservation of some higher mass polycyclic aromatic hydrocarbons (PAHs) compared with the non-impacted sample. Each impactor type shows unique impactor residue morphologies produced at a given impact velocity. An expanded methodology is presented to announce relatively new analytical techniques together with innovative modifications to other methods that can be used to characterize small impact residues in LDEF craters, in addition to other acquired extraterrestrial samples

The Mesolithic-Neolithic transition in western Scotland and its European context

The transition is considered in terms of four related questions: (i) HOW did the shift from foraging to farming happen? (ii) WHY did it happen? (iii) WHEN did it happen? (iv) WHY did it happen WHEN it did? The adoption of farming coincided with a shift to a more continental-type climate with lower winter precipitation, which improved the prospects for cereal cultivation. It is sug- gested that this was a key factor in the transition from Mesolithic to Neolithic across north-west Eu- rope as a whole.Mezolitsko-neolitski prehod obravnavamo glede na štiri povezana vprašanja: (i) KAKO se je zgodil prehod iz lovstva-nabiralništva v kmetovanje? (ii) ZAKAJ se je zgodil? (iii) KDAJ se je zgodil? (iv) ZAKAJ se je zgodil, KO se je zgodil? Do prevzema kmetovanja je prišlo v času, ko so klimatske razmere postale bolj kontinentalne in zimske padavine manj obilne. To je izboljšalo pogoje za gojenje žit. Menimo, da je bil to ključni dejavnik za prehod iz mezolitika v neolitik v celotni severozahodni Evropi

Indigenous Narratives: Global Forces in Motion

This is the guest editors' introduction to the Spring/Summer 2019 special issue

Dispersive readout of a flux qubit at the single photon level

A superconducting flux qubit is inductively coupled to a Superconducting QUantum Interference Device (SQUID) magnetometer, capacitively shunted to form a 1.294-GHz resonator. The qubit-state-dependent resonator frequency is weakly probed with a microwave signal and detected with a Microstrip SQUID Amplifier. At a mean resonator occupation $\bar{n}$ = 1.5 photons, the readout visibility is increased by a factor of 4.5 over that using a cryogenic semiconductor amplifier. As $\bar{n}$ is increased from 0.008 to 0.1, no reduction in $T_1$ is observed, potentially enabling continuous monitoring of the qubit state.Comment: 5 pages, 5 figure

The s Process: Nuclear Physics, Stellar Models, Observations

Nucleosynthesis in the s process takes place in the He burning layers of low mass AGB stars and during the He and C burning phases of massive stars. The s process contributes about half of the element abundances between Cu and Bi in solar system material. Depending on stellar mass and metallicity the resulting s-abundance patterns exhibit characteristic features, which provide comprehensive information for our understanding of the stellar life cycle and for the chemical evolution of galaxies. The rapidly growing body of detailed abundance observations, in particular for AGB and post-AGB stars, for objects in binary systems, and for the very faint metal-poor population represents exciting challenges and constraints for stellar model calculations. Based on updated and improved nuclear physics data for the s-process reaction network, current models are aiming at ab initio solution for the stellar physics related to convection and mixing processes. Progress in the intimately related areas of observations, nuclear and atomic physics, and stellar modeling is reviewed and the corresponding interplay is illustrated by the general abundance patterns of the elements beyond iron and by the effect of sensitive branching points along the s-process path. The strong variations of the s-process efficiency with metallicity bear also interesting consequences for Galactic chemical evolution.Comment: 53 pages, 20 figures, 3 tables; Reviews of Modern Physics, accepte

The social geography of unmarried cohabitation in the USA, 2007-2011

US studies of marriage and cohabitation have mainly highlighted the social and racial differentials as they were observed in cross-sections, and have as a result essentially focused on the "pattern of disadvantage". The evolution of such social differentials over time and space reveals that this pattern of disadvantage has clearly persisted, but that it is far from covering the whole story. Historically, there has been a major contribution to the rise of cohabitation by white college students, and later on young white adults with higher education continued to start unions via cohabitation to ever increasing degrees. Only, they seem to move into marriage to a greater extent later on in life than other population segments. Also, the religious affiliation matters greatly: Mormons and evangelical Christians have resisted the current trends. Furthermore this effect is not only operating at the individual but at the contextual level as well. Conversely, even after controls for competing socio-economic explanations, residence in areas (either counties or PUMA-areas) with a Democratic voting pattern is related to higher cohabitation probabilities. And, finally, different legal contexts at the level of States also significantly contributed to the emergence of strong spatial contrasts. Hence, there is a concurrence of several factors shaping the present differentiations, and the rise of secular and liberal attitudes, i.e. the "ethics revolution", is equally a part of the explanation

Universal Cubic Eigenvalue Repulsion for Random Normal Matrices

Random matrix models consisting of normal matrices, defined by the sole constraint $[N^{\dag},N]=0$, will be explored. It is shown that cubic eigenvalue repulsion in the complex plane is universal with respect to the probability distribution of matrices. The density of eigenvalues, all correlation functions, and level spacing statistics are calculated. Normal matrix models offer more probability distributions amenable to analytical analysis than complex matrix models where only a model wth a Gaussian distribution are solvable. The statistics of numerically generated eigenvalues from gaussian distributed normal matrices are compared to the analytical results obtained and agreement is seen.Comment: 15 pages, 2 eps figures. to appar in Physical Review