12,003 research outputs found
Electric field distortions in structures of the twist bend nematic (NTB) phase of a bent-core liquid crystal
Dielectric spectroscopy of a twist bend nematic phase of an achiral bent core
liquid crystalline compound under DC bias is used to investigate its response
to electric field. Two collective relaxation processes are revealed, these are
assigned to distortions of helicoidal structure by the external bias field.
Frequency of the mode depends primarily on the helicoidal angle and has
anomalous, softening- like behaviour at the nematic to the twist bend nematic
transition. A coupling of dielectric anisotropy with electric field gives rise
to a new equilibrium periodic structure in the time scale involved. The modulus
of the wave vector gradually vanishes on increasing the bias field (except for
the initial behaviour, which is just the opposite). Transition from the twist
bend to the splay bend structure is clearly observed by a sudden drop in the
frequency of this mode, which decreases almost linearly with increasing field.
Results agree with predictions from current models for the periodically
distorted a twist bend nematic phase.Comment: 14 PAGES, 7 FIGURES, submitted to Physical Review Letter
Randomized Benchmarking as Convolution: Fourier Analysis of Gate Dependent Errors
We provide an alternative proof of Wallman's [Quantum 2, 47 (2018)] and
Proctor's [Phys. Rev. Lett. 119, 130502 (2017)] bounds on the effect of
gate-dependent noise on randomized benchmarking (RB). Our primary insight is
that a RB sequence is a convolution amenable to Fourier space analysis, and we
adopt the mathematical framework of Fourier transforms of matrix-valued
functions on groups established in recent work from Gowers and Hatami [Sbornik:
Mathematics 208, 1784 (2017)]. We show explicitly that as long as our faulty
gate-set is close to some representation of the Clifford group, an RB sequence
is described by the exponential decay of a process that has exactly two
eigenvalues close to one and the rest close to zero. This framework also allows
us to construct a gauge in which the average gate-set error is a depolarizing
channel parameterized by the RB decay rates, as well as a gauge which maximizes
the fidelity with respect to the ideal gate-set
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Arts, Culture and the Making of Global Cities. Creating New Urban Landscapes in Asia. (Eds.) Kong, Lily; Chia-ho, Ching and Tsu-Lung, Chou (2015). Edward Elgar: Cheltenham, Northampton
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Daniel Silver and Grodach, Carl 2013 (eds): The Politics of Urban Cultural Policy. Global Perspectives. London and New York: Routledge
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‘Freelance isn’t free.’ Coworking as a critical urban practice to cope with informality in creative labour markets
For more than a decade, co-working spaces have proliferated in cities worldwide. The paper discusses co-working as a critical urban practice because these spaces give support to the rising number of freelance workers in culture and creative industries. Freelance workers are an ‘invisible’ workforce whose impact often remains ‘hidden’ (Mould et al. 2014), who are not sufficiently protected through social welfare regulations and do not enjoy the same social entitlements as employed workers. This paper uses the concept of informality to highlight ongoing informalisation processes of employment relationships as well as informal working practices in creative labour markets. It discusses the emergence of co-working as a practice of collective self-help and self-organisation to cope with and to potentially overcome the informality, uncertainty and risks associated with independent work. It argues that co-working can be seen in line with other practices of informal urbanism that become more prevalent in European and North American cities due to the lack of affordable housing, the retrenchment of the social welfare state and the imposed conditions of ‘austerity urbanism’ (Peck 2012
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Coworking in the city
In the aftermath of the financial and economic crisis of 2007 and 2008, a new type of collaboratively oriented workplace has emerged in cities. These coworking spaces and the associated practice of coworking exemplify new ways of organising labour in project-based and largely freelance occupations as found in the cultural and creative industries. But coworking spaces are not just flexible shared office spaces for creative professionals ‘working alone together’ (Spinuzzi, 2012). Coworking promotes a collective, community-based approach to the organisation of cultural and creative work where a particularly important role is accorded to the coworking host, whose activities are described as a curatorial practice aimed at creating a collaborative atmosphere and social relationships. Coworking spaces can therefore be regarded as a new form of urban social infrastructure enabling contacts and collaborations between people, ideas and connecting places
Generation and detection of NOON states in superconducting circuits
NOON states, states between two modes of light of the form
allow for super-resolution interformetry. We
show how NOON states can be efficiently produced in circuit quntum
electrodynamics using superconducting phase qubits and resonators. We propose a
protocol where only one interaction between the two modes is required, creating
all the necessary entanglement at the start of the procedure. This protocol
makes active use of the first three states of the phase qubits. Additionally,
we show how to efficiently verify the success of such an experiment, even for
large NOON states, using randomly sampled measurements and semidefinite
programming techniques.Comment: 15 pages and 3 figure
The Predictive Validity of Mathematics Curriculum-Based Measurement on Smarter Balanced Assessment Consortium Mathematics Scores
The purpose of this study was to examine the predicative validity of computation curriculumbased measurement (CBM) on mathematics Smarter Balanced Assessment Consortium scores (SBAC). This study looked at one cohort consisting of 2,741 participants in third, fourth, and fifth grade during the 2017-2018 school year in one school district in Oregon. This study used a hierarchical multiple regression to examine the relationship between CBM and mathematics SBAC. Additionally, this study looked at the extent to which gender, ethnicity, special education status (SPED) and English language learner (ELL) status interacted with CBM scores to predict end-of-year mathematics SBAC scores. The findings of this study indicate that CBM scores predict math SBAC scores in third, fourth, and fifth grade to a modest extent. The findings also indicate that taken together, CBM scores, gender, ethnicity, special education status, and English language learner status predict math SBAC scores to a moderate extent
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