1,214 research outputs found
Polyethylene naphthalate film as a wavelength shifter in liquid argon detectors
Liquid argon-based scintillation detectors are important for dark matter
searches and neutrino physics. Argon scintillation light is in the vacuum
ultraviolet region, making it hard to be detected by conventional means.
Polyethylene naphthalate (PEN), an optically transparent thermoplastic
polyester commercially available as large area sheets or rolls, is proposed as
an alternative wavelength shifter to the commonly-used tetraphenyl butadiene
(TPB). By combining the existing literature data and spectrometer measurements
relative to TPB, we conclude that the fluorescence yield and timing of both
materials may be very close. The evidence collected suggests that PEN is a
suitable replacement for TPB in liquid argon neutrino detectors, and is also a
promising candidate for dark matter detectors. Advantages of PEN are discussed
in the context of scaling-up existing technologies to the next generation of
very large ktonne-scale detectors. Its simplicity has a potential to facilitate
such scale-ups, revolutionizing the field.Comment: 6 pages, 3 figure
Boson condensation and instability in the tensor network representation of string-net states
The tensor network representation of many-body quantum states, given by local
tensors, provides a promising numerical tool for the study of strongly
correlated topological phases in two dimension. However, tensor network
representations may be vulnerable to instabilities caused by small
perturbations of the local tensor, especially when the local tensor is not
injective. For example, the topological order in tensor network representations
of the toric code ground state has been shown to be unstable under certain
small variations of the local tensor, if these small variations do not obey a
local symmetry of the tensor. In this paper, we ask the questions of
whether other types of topological orders suffer from similar kinds of
instability and if so, what is the underlying physical mechanism and whether we
can protect the order by enforcing certain symmetries on the tensor. We answer
these questions by showing that the tensor network representation of all
string-net models are indeed unstable, but the matrix product operator (MPO)
symmetries of the local tensor can help to protect the order. We find that,
`stand-alone' variations that break the MPO symmetries lead to instability
because they induce the condensation of bosonic quasi-particles and destroy the
topological order in the system. Therefore, such variations must be forbidden
for the encoded topological order to be reliably extracted from the local
tensor. On the other hand, if a tensor network based variational algorithm is
used to simulate the phase transition due to boson condensation, then such
variation directions must be allowed in order to access the continuous phase
transition process correctly.Comment: 44 pages, 85 figures, comments welcom
Let’s Talk About Money: The Role of Attachment Styles in Couples’ Financial Communication, Financial Management, and Financial Conflict
There are many households with financial problems, but most research on financial management is restricted to individual effects, not taking into account the relationship these individuals are in. The current investigation tests whether a person’s attachment style predicts how comfortable they are talking about financial issues with their partner and how that relates to different financial outcome variables. Two cross-sectional survey studies in the Netherlands and the US, each with more than 100 participants show that a higher score on anxious attachment is related to less communication about money with one’s partner. Less financial communication is related to worse financial management within the couple, which in turn predicts conflicts about money. A third survey with 770 participants shows that less financial communication is related to more financial problems. These findings highlight the need to take relationship variables into account to understand financial processes in couples
Symmetry protection of topological order in one-dimensional quantum spin systems
We discuss the characterization and stability of the Haldane phase in integer
spin chains on the basis of simple, physical arguments. We find that an odd-
Haldane phase is a topologically non-trivial phase which is protected by any
one of the following three global symmetries: (i) the dihedral group of
-rotations about and axes; (ii) time-reversal symmetry
; (iii) link inversion symmetry (reflection
about a bond center), consistently with previous results [Phys. Rev. B
\textbf{81}, 064439 (2010)]. On the other hand, an even- Haldane phase is
not topologically protected (i.e., it is indistinct from a trivial,
site-factorizable phase). We show some numerical evidence that supports these
claims, using concrete examples.Comment: 9 pages, 6 figures, extended version: several new examples and
numerical results added. Journal reference adde
Detection of Symmetry Protected Topological Phases in 1D
A topological phase is a phase of matter which cannot be characterized by a
local order parameter. It has been shown that gapped phases in 1D systems can
be completely characterized using tools related to projective representations
of the symmetry groups. We show how to determine the matrices of these
representations in a simple way in order to distinguish between different
phases directly. From these matrices we also point out how to derive several
different types of non-local order parameters for time reversal, inversion
symmetry and symmetry, as well as some more general cases
(some of which have been obtained before by other methods). Using these
concepts, the ordinary string order for the Haldane phase can be related to a
selection rule that changes at the critical point. We furthermore point out an
example of a more complicated internal symmetry for which the ordinary string
order cannot be applied.Comment: 12 pages, 9 Figure
Brief Report: Examining the Link Between Autistic Traits and Compulsive Internet Use in a Non-Clinical Sample
Individuals with autism spectrum disorders or autistic traits may profit from Internet and computer-mediated interactions, but there is concern about their Internet use becoming compulsive. This study investigated the link between autistic traits and Internet use in a 2-wave longitudinal study with a non-clinical community sample (n = 390). As compared to people with less autistic traits, people with more autistic traits did not report a higher frequency of Internet use, but they were more prone to compulsive Internet use. For women, more autistic traits predicted an increase in compulsive Internet use over time. These results suggest that, despite its appeal for people with autistic traits, the Internet carries the risk of compulsive use
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