475 research outputs found
The Construction of Sport Heritage Attractions
Sport can be heritage, and sport heritage attractions such as halls of fame,
museums, and stadium tours can be one of the more potent forms of heritage
tourism. However, few studies have examined sport heritage attractions, nor
considered their construction. This paper examines three ways in which sport
heritage attractions are constructed, exploring in particular the human dimensions of
sport heritage, the link between sport heritage and legacy, and the relationship
between sport heritage, tourism and globalization. Several outcomes of these
constructions are examined, both in terms of the representation sport heritage as
well as implications for the attractions themselves. Ultimately, this paper seeks to
consider sport heritage, and its constituent attractions, in wider heritage and heritage
tourism debates
Remarks on NonHamiltonian Statistical Mechanics: Lyapunov Exponents and Phase-Space Dimensionality Loss
The dissipation associated with nonequilibrium flow processes is reflected by
the formation of strange attractor distributions in phase space. The
information dimension of these attractors is less than that of the equilibrium
phase space, corresponding to the extreme rarity of nonequilibrium states. Here
we take advantage of a simple model for heat conduction to demonstrate that the
nonequilibrium dimensionality loss can definitely exceed the number of
phase-space dimensions required to thermostat an otherwise Hamiltonian system.Comment: 5 pages, 2 figures, minor typos correcte
Strong increase in ultrasound attenuation below T2 in Sr2RuO4 : possible evidence for domains
Funding information: B.J.R. and S.G. acknowledge support from the Office of Basic Energy Sciences of the U.S. Department of Energy under award No. DE-SC0020143. B.J.R. and S.G. acknowledge support from the Cornell Center for Materials Research with funding from the Materials Research Science and Engineering Centers program of the National Science Foundation (cooperative agreement No. DMR-1719875). T.G.K. acknowledges support from the National Science Foundation under Grant No. PHY-2110250. N.K. acknowledges support from Japan Society for the Promotion of Science (JSPS) KAKENHI (Grants No. JP17H06136, No. JP18K04715, and No. 21H01033) and Japan Science and Technology Agency Mirai Program (JPMJMI18A3) in Japan.Recent experiments suggest that Sr2RuO4 has a two-component superconducting order parameter (OP). A two-component OP has multiple degrees of freedom in the superconducting state that can result in low-energy collective modes or the formation of domain walls—a possibility that would explain a number of experimental observations including the smallness of the signature of time reversal symmetry breaking at Tc and telegraph noise in critical current experiments. We use resonant ultrasound spectroscopy to perform ultrasound attenuation measurements across the superconducting Tc of Sr2RuO4. We find that compressional sound attenuation increases by a factor of 7 immediately below Tc , in sharp contrast with what is found in both conventional (s-wave) and high-Tc (d-wave) superconductors. Our observations are most consistent with the presence of domain walls that separate different configurations of the superconducting OP. The fact that we only observe an increase in sound attenuation for compressional strains, and not for shear strains, suggests an inhomogeneous superconducting state formed of two distinct, accidentally degenerate superconducting OPs that are not related to each other by symmetry. Whatever the mechanism, a factor of 7 increase in sound attenuation is a singular characteristic that must be reconciled with any potential theory of superconductivity in Sr2RuO4.Publisher PDFPeer reviewe
Scale-invariant magnetoresistance in a cuprate superconductor
The anomalous metallic state in high-temperature superconducting cuprates is
masked by the onset of superconductivity near a quantum critical point. Use of
high magnetic fields to suppress superconductivity has enabled a detailed study
of the ground state in these systems. Yet, the direct effect of strong magnetic
fields on the metallic behavior at low temperatures is poorly understood,
especially near critical doping, . Here we report a high-field
magnetoresistance study of thin films of \LSCO cuprates in close vicinity to
critical doping, . We find that the metallic state
exposed by suppressing superconductivity is characterized by a
magnetoresistance that is linear in magnetic field up to the highest measured
fields of T. The slope of the linear-in-field resistivity is
temperature-independent at very high fields. It mirrors the magnitude and
doping evolution of the linear-in-temperature resistivity that has been
ascribed to Planckian dissipation near a quantum critical point. This
establishes true scale-invariant conductivity as the signature of the strange
metal state in the high-temperature superconducting cuprates.Comment: 10 pages, 3 figure
On the Geometry and Entropy of Non-Hamiltonian Phase Space
We analyze the equilibrium statistical mechanics of canonical, non-canonical
and non-Hamiltonian equations of motion by throwing light into the peculiar
geometric structure of phase space. Some fundamental issues regarding time
translation and phase space measure are clarified. In particular, we emphasize
that a phase space measure should be defined by means of the Jacobian of the
transformation between different types of coordinates since such a determinant
is different from zero in the non-canonical case even if the phase space
compressibility is null. Instead, the Jacobian determinant associated with
phase space flows is unity whenever non-canonical coordinates lead to a
vanishing compressibility, so that its use in order to define a measure may not
be always correct. To better illustrate this point, we derive a mathematical
condition for defining non-Hamiltonian phase space flows with zero
compressibility. The Jacobian determinant associated with time evolution in
phase space is altogether useful for analyzing time translation invariance. The
proper definition of a phase space measure is particularly important when
defining the entropy functional in the canonical, non-canonical, and
non-Hamiltonian cases. We show how the use of relative entropies can circumvent
some subtle problems that are encountered when dealing with continuous
probability distributions and phase space measures. Finally, a maximum
(relative) entropy principle is formulated for non-canonical and
non-Hamiltonian phase space flows.Comment: revised introductio
Scale-invariant magnetic anisotropy in RuCl at high magnetic fields
In RuCl, inelastic neutron scattering and Raman spectroscopy reveal a
continuum of non-spin-wave excitations that persists to high temperature,
suggesting the presence of a spin liquid state on a honeycomb lattice. In the
context of the Kitaev model, magnetic fields introduce finite interactions
between the elementary excitations, and thus the effects of high magnetic
fields - comparable to the spin exchange energy scale - must be explored. Here
we report measurements of the magnetotropic coefficient - the second derivative
of the free energy with respect to magnetic field orientation - over a wide
range of magnetic fields and temperatures. We find that magnetic field and
temperature compete to determine the magnetic response in a way that is
independent of the large intrinsic exchange interaction energy. This emergent
scale-invariant magnetic anisotropy provides evidence for a high degree of
exchange frustration that favors the formation of a spin liquid state in
RuCl.Comment: arXiv admin note: substantial text overlap with arXiv:1901.09245.
Nature Physic
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Magnetoresistance Scaling Reveals Symmetries of the Strongly Correlated Dynamics in BaFe_{2}(As_{1-x}P_{x})_{2}.
The phenomenon of T-linear resistivity commonly observed in a number of strange metals has been widely seen as evidence for the breakdown of the quasiparticle picture of metals. This study shows that a recently discovered H/T scaling relationship in the magnetoresistance of the strange metal BaFe_{2}(As_{1-x}P_{x})_{2} is independent of the relative orientations of current and magnetic field. Rather, its magnitude and form depend only on the orientation of the magnetic field with respect to a single crystallographic axis: the direction perpendicular to the magnetic iron layers. This finding suggests that the magnetotransport scaling does not originate from the conventional averaging or orbital velocity of quasiparticles as they traverse a Fermi surface, but rather from dissipation arising from two-dimensional correlations
Path Integral for Quantum Operations
In this paper we consider a phase space path integral for general
time-dependent quantum operations, not necessarily unitary. We obtain the path
integral for a completely positive quantum operation satisfied Lindblad
equation (quantum Markovian master equation). We consider the path integral for
quantum operation with a simple infinitesimal generator.Comment: 24 pages, LaTe
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