1,583 research outputs found
Passive interferometric symmetries of multimode Gaussian pure states
As large-scale multimode Gaussian states begin to become accessible in the
laboratory, their representation and analysis become a useful topic of research
in their own right. The graphical calculus for Gaussian pure states provides
powerful tools for their representation, while this work presents a useful tool
for their analysis: passive interferometric (i.e., number-conserving)
symmetries. Here we show that these symmetries of multimode Gaussian states
simplify calculations in measurement-based quantum computing and provide
constructive tools for engineering large-scale harmonic systems with specific
physical properties, and we provide a general mathematical framework for
deriving them. Such symmetries are generated by linear combinations of
operators expressed in the Schwinger representation of U(2), called nullifiers
because the Gaussian state in question is a zero eigenstate of them. This
general framework is shown to have applications in the noise analysis of
continuous-various cluster states and is expected to have additional
applications in future work with large-scale multimode Gaussian states.Comment: v3: shorter, included additional applications, 11 pages, 7 figures.
v2: minor content revisions, additional figures and explanation, 23 pages, 18
figures. v1: 22 pages, 16 figure
Coexistence of glassy antiferromagnetism and giant magnetoresistance (GMR) in Fe/Cr multilayer structures
Using temperature-dependent magnetoresistance and magnetization measurements
on Fe/Cr multilayers that exhibit pronounced giant magnetoresistance (GMR), we
have found evidence for the presence of a glassy antiferromagnetic (GAF) phase.
This phase reflects the influence of interlayer exchange coupling (IEC) at low
temperature (T < 140K) and is characterized by a field-independent glassy
transition temperature, Tg, together with irreversible behavior having
logarithmic time dependence below a "de Almeida and Thouless" (AT) critical
field line. At room temperature, where the GMR effect is still robust, IEC
plays only a minor role, and it is the random potential variations acting on
the magnetic domains that are responsible for the antiparallel interlayer
domain alignment.Comment: 5 pages, 4 figure
High Multiplicity Scheduling with Switching Costs for few Products
We study a variant of the single machine capacitated lot-sizing problem with
sequence-dependent setup costs and product-dependent inventory costs. We are
given a single machine and a set of products associated with a constant demand
rate, maximum loading rate and holding costs per time unit. Switching
production from one product to another incurs sequencing costs based on the two
products. In this work, we show that by considering the high multiplicity
setting and switching costs, even trivial cases of the corresponding "normal"
counterparts become non-trivial in terms of size and complexity. We present
solutions for one and two products.Comment: 10 pages (4 appendix), to be published in Operations Research
Proceedings 201
Large modulation of the Shubnikov-de Haas oscillations by the Rashba interaction at the LaAlO/SrTiO interface
We investigate the 2-dimensional Fermi surface of high-mobility
LaAlO/SrTiO interfaces using Shubnikov-de Haas oscillations. Our
analysis of the oscillation pattern underscores the key role played by the
Rashba spin-orbit interaction brought about by the breaking of inversion
symmetry, as well as the dominant contribution of the heavy /
orbitals on electrical transport. We furthermore bring into light the complex
evolution of the oscillations with the carrier density, which is tuned by the
field effect
Tunable Rashba spin-orbit interaction at oxide interfaces
The quasi-two-dimensional electron gas found at the LaAlO3/SrTiO3 interface
offers exciting new functionalities, such as tunable superconductivity, and has
been proposed as a new nanoelectronics fabrication platform. Here we lay out a
new example of an electronic property arising from the interfacial breaking of
inversion symmetry, namely a large Rashba spin-orbit interaction, whose
magnitude can be modulated by the application of an external electric field. By
means of magnetotransport experiments we explore the evolution of the
spin-orbit coupling across the phase diagram of the system. We uncover a steep
rise in Rashba interaction occurring around the doping level where a quantum
critical point separates the insulating and superconducting ground states of
the system
Doing Biopolitics Differently? Radical Potential in the Post-2015 MDG and SDG Debates
Post print On institutional repository or subject-based repository after a 18 months embargo, withdraw
Helium condensation in aerogel: avalanches and disorder-induced phase transition
We present a detailed numerical study of the elementary condensation events
(avalanches) associated to the adsorption of He in silica aerogels. We use
a coarse-grained lattice-gas description and determine the nonequilibrium
behavior of the adsorbed gas within a local mean-field analysis, neglecting
thermal fluctuations and activated processes. We investigate the statistical
properties of the avalanches, such as their number, size and shape along the
adsorption isotherms as a function of gel porosity, temperature, and chemical
potential. Our calculations predict the existence of a line of critical points
in the temperature-porosity diagram where the avalanche size distribution
displays a power-law behavior and the adsorption isotherms have a universal
scaling form. The estimated critical exponents seem compatible with those of
the field-driven Random Field Ising Model at zero temperature.Comment: 16 pages, 14 figure
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