190 research outputs found
Magnetic-Based Contact and Non-Contact Manipulation of Cell Mockups and MCF-7 Human Breast Cancer Cells
Low-Loss All-Optical Zeno Switch in a Microdisk Cavity Using EIT
We present theoretical results of a low-loss all-optical switch based on
electromagnetically induced transparency and the classical Zeno effect in a
microdisk resonator. We show that a control beam can modify the atomic
absorption of the evanescent field which suppresses the cavity field buildup
and alters the path of a weak signal beam. We predict more than 35 dB of
switching contrast with less than 0.1 dB loss using just 2 micro-Watts of
control-beam power for signal beams with less than single photon intensities
inside the cavity.Comment: Updated with new references, corrected Eq 2a, and added introductory
text. 7 pages, 5 figures, 3 table
Screening of qubit from zero-temperature reservoir
We suggest an application of dynamical Zeno effect to isolate a qubit in the
quantum memory unit against decoherence caused by coupling with the reservoir
having zero temperature. The method is based on using an auxiliary casing
system that mediate the qubit-reservoir interaction and is simultaneously
frequently erased to ground state. This screening procedure can be implemented
in the cavity QED experiments to store the atomic and photonic qubit states.Comment: 4 pages, 5 figure
Non-Fermi liquid regime of a doped Mott insulator
We study the doping of a Mott insulator in the presence of quenched
frustrating disorder in the magnetic exchange. A low doping regime
is found, in which the quasiparticle coherent scale is low : with (the ratio of typical exchange to
hopping). In the ``quantum critical regime'' , several
physical quantities display Marginal Fermi Liquid behaviour : NMR relaxation
time , resistivity , optical lifetime
\tau_{opt}^{-1}\propto \omega/\ln(\omega/\epstar) and response functions obey
scaling, e.g. .
In contrast, single-electron properties display stronger deviations from Fermi
liquid theory in this regime with a dependence of the inverse
single-particle lifetime and a decay of the photoemission
intensity. On the basis of this model and of various experimental evidence, it
is argued that the proximity of a quantum critical point separating a glassy
Mott-Anderson insulator from a metallic ground-state is an important ingredient
in the physics of the normal state of cuprate superconductors (particularly the
Zn-doped materials). In this picture the corresponding quantum critical regime
is a ``slushy'' state of spins and holes with slow spin and charge dynamics
responsible for the anomalous properties of the normal state.Comment: 40 pages, RevTeX, including 13 figures in EPS. v2 : minor changes,
some references adde
Embedded 3D printing of dilute particle suspensions into dense complex tissue fibers using shear thinning xanthan baths
In order to fabricate functional organoids and microtissues, a high cell density is generally required. As such, the placement of cell suspensions in molds or microwells to allow for cell concentration by sedimentation is the current standard for the production of organoids and microtissues. Even though molds offer some level of control over the shape of the resulting microtissue, this control is limited as microtissues tend to compact towards a sphere after sedimentation of the cells. 3D bioprinting on the other hand offers complete control over the shape of the resulting structure. Even though the printing of dense cell suspensions in the ink has been reported, extruding dense cellular suspensions is challenging and generally results in high shear stresses on the cells and a poor shape fidelity of the print. As such, additional materials such as hydrogels are added in the bioink to limit shear stresses, and to improve shape fidelity and resolution. The maximum cell concentration that can be incorporated in a hydrogel-based ink before the ink's rheological properties are compromised, is significantly lower than the concentration in a tissue equivalent. Additionally, the hydrogel components often interfere with cellular self-assembly processes. To circumvent these limitations, we report a simple and inexpensive xanthan bath based embedded printing method to 3D print dense functional linear tissues using dilute particle suspensions consisting of cells, spheroids, hydrogel beads, or combinations thereof. Using this method, we demonstrated the self-organization of functional cardiac tissue fibers with a layer of epicardial cells surrounding a body of cardiomyocytes
The rms-flux relations in different branches in Cyg X-2
In this paper, the rms-flux (root mean square-flux) relation along the
Z-track of the bright Z-Source Cyg X-2 is analyzed using the observational data
of Rossi X-ray Timing Explorer (RXTE). Three types of rms-flux relations, i.e.
positive, negative, and 'arch'-like correlations are found in different
branches. The rms is positively correlated with flux in normal branch (NB), but
anti-correlated in the vertical horizontal branch (VHB). The rms-flux relation
shows an 'arch'-like shape in the horizontal branch (HB). We also try to
explain this phenomenon using existing models.Comment: Accepted for publication in Astrophysics & Space Scienc
Distributed phase-covariant cloning with atomic ensembles via quantum Zeno dynamics
We propose an interesting scheme for distributed orbital state quantum
cloning with atomic ensembles based on the quantum Zeno dynamics. These atomic
ensembles which consist of identical three-level atoms are trapped in distant
cavities connected by a single-mode integrated optical star coupler. These
qubits can be manipulated through appropriate modulation of the coupling
constants between atomic ensemble and classical field, and the cavity decay can
be largely suppressed as the number of atoms in the ensemble qubits increases.
The fidelity of each cloned qubit can be obtained with analytic result. The
present scheme provides a new way to construct the quantum communication
network.Comment: 5 pages, 4 figure
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