28 research outputs found
Immunity of information encoded in decoherence-free subspaces to particle loss
We demonstrate that for an ensemble of qudits, subjected to collective
decoherence in the form of perfectly correlated random SU(d) unitaries, quantum
superpositions stored in the decoherence free subspace are fully immune against
the removal of one particle. This provides a feasible scheme to protect quantum
information encoded in the polarization state of a sequence of photons against
both collective depolarization and one photon loss, and can be demonstrated
with photon quadruplets using currently available technology.Comment: to appear in Phys. Rev. A; 5 pages, 2 figures; content changed a bit
(the property demonstrated explicitly on a 4 qubit state
Rheological analysis of Blast Furnace Synthetic Slag Admixtures of Al2O3
It is common for researchers to believe that liquid slag is a fluid characterized by rheological behavior of ideally viscous Newtonian body. At the same time it is assumed that the fluid is similar to synthetic polymers in terms of its structure. The authors of this paper conducted research into 4-component liquid and solid-liquid synthetic slag system: CaO–SiO2–MgO–Al2O3 The research involved graphite measurement systems. A perforated spindle was used for the solid-liquid systems subject to shear stress, whereas a smooth one was used for fully liquid systems. Both measurement systems worked according to Searle’s system. This paper presents selected rheological research results concerning oxide solutions in high temperatures and their rheological analysis
Qubism: self-similar visualization of many-body wavefunctions
A visualization scheme for quantum many-body wavefunctions is described,
which we have termed qubism. Its main property is its recursivity: increasing
the number of qubits reflects in an increase in the image resolution. Thus, the
plots are typically fractal. As examples, we provide images for the ground
states of commonly used Hamiltonians in condensed matter and cold atom physics,
such as Heisenberg or ITF. Many features of the wavefunction, such as
magnetization, correlations and criticality, can be visualized as properties of
the images. In particular, factorizability can be easily spotted, and a way to
estimate the entanglement entropy from the image is provided
Community Detection in Quantum Complex Networks
Determining community structure is a central topic in the study of complex
networks, be it technological, social, biological or chemical, in static or
interacting systems. In this paper, we extend the concept of community
detection from classical to quantum systems---a crucial missing component of a
theory of complex networks based on quantum mechanics. We demonstrate that
certain quantum mechanical effects cannot be captured using current classical
complex network tools and provide new methods that overcome these problems. Our
approaches are based on defining closeness measures between nodes, and then
maximizing modularity with hierarchical clustering. Our closeness functions are
based on quantum transport probability and state fidelity, two important
quantities in quantum information theory. To illustrate the effectiveness of
our approach in detecting community structure in quantum systems, we provide
several examples, including a naturally occurring light-harvesting complex,
LHCII. The prediction of our simplest algorithm, semiclassical in nature,
mostly agrees with a proposed partitioning for the LHCII found in quantum
chemistry literature, whereas our fully quantum treatment of the problem
uncovers a new, consistent, and appropriately quantum community structure.Comment: 16 pages, 4 figures, 1 tabl
Zespół Aspergera, nauki ścisłe i kultura nerdów
Asperger Syndrome, Hard Science and Nerd Culture In this paper we analyse selected psychological and cultural aspects of the Asperger Syndrome (a mild form of autism). We present its characteristic cognitive style and compare it to that of the hard sciences. Our claims about this connection are supported by some empirical data. Additionally, we investigate similarities in the social behaviour of people with Asperger Syndrome and nerds (i.e. intelligent people with deep interests, but also with certain social difficulties)