702 research outputs found
Invariants for a Class of Nongeneric Three-qubit States
We investigate the equivalence of quantum states under local unitary
transformations. A complete set of invariants under local unitary
transformations is presented for a class of non-generic three-qubit mixed
states. It is shown that two such states in this class are locally equivalent
if and only if all these invariants have equal values for them.Comment: 7 page
Applicability of Relativistic Point-Coupling Models to Neutron Star Physics
Comparing with a wide range of covariant energy density functional models
based on the finite-range meson-exchange representation, the relativistic
mean-field models with the zero-range contact interaction, namely the
relativistic point-coupling models, are still infrequent to be utilized in
establishing nuclear equation of state (EoS) and investigating neutron star
properties, although comprehensive applications and achievements of them in
describing many nuclear properties both in ground and exited states are mature.
In this work, the EoS of neutron star matter is established constructively in
the framework of the relativistic point-coupling models to study neutron star
physics. Taking two selected functionals DD-PC1 and PC-PK1 as examples, nuclear
symmetry energies and several neutron star properties including proton
fractions, mass-radius relations, the core-crust transition density, the
fraction of crustal moment of inertia and dimensionless tidal deformabilities
are discussed. A suppression of pressure of neutron star matter found in the
functional PC-PK1 at high densities results in the difficulty of its prediction
when approaching to the maximum mass of neutron stars. In addition, the
divergences between two selected functionals in describing neutron star
quantities mentioned above are still large, ascribing to the less constrained
behavior of these functionals at high densities. Then it is expected that the
constraints on the dense matter EoS from precise and massive modern
astronomical observations, such as the tidal-deformabilities taken from
gravitational-wave events, would be essential to improve the parameterizing of
the relativistic point-coupling models.Comment: To appear in the AIP Proceedings of the Xiamen-CUSTIPEN Workshop on
the EOS of Dense Neutron-Rich Matter in the Era of Gravitational Wave
Astronomy, Jan. 3-7, Xiamen, Chin
Orbital Kondo effect in a parallel double quantum dot
We construct a theoretical model to study the orbital Kondo effect in a
parallel double quantum dot (DQD). Recently, pseudospin-resolved transport
spectroscopy of the orbital Kondo effect in a DQD has been experimentally
reported. The experiment revealed that when interdot tunneling is ignored,
there exist two and one Kondo peaks in the conductance-bias curve for the
pseudospin-non-resolved and pseudospin-resolved cases, respectively. Our
theoretical studies reproduce this experimental result. We also investigate the
situation of all lead voltages being non-equal (the complete
pseudospin-resolved case), and find that there are four Kondo peaks at most in
the curve of the conductance versus the pseudospin splitting energy. When the
interdot tunneling is introduced, some new Kondo peaks and dips can emerge.
Besides, the pseudospin transport and the pseudospin flipping current are also
studied in the DQD system. Since the pseudospin transport is much easier to be
controlled and measured than the real spin transport, it can be used to study
the physical phenomenon related to the spin transport.Comment: 18 pages, 7 figures, accepted by J. Phys.: Condens. Matter in
September 201
Theory for electric dipole superconductivity with an application for bilayer excitons
Exciton superfluid is a macroscopic quantum phenomenon in which large
quantities of excitons undergo the Bose-Einstein condensation. Recently,
exciton superfluid has been widely studied in various bilayer systems. However,
experimental measurements only provide indirect evidence for the existence of
exciton superfluid. In this article, by viewing the exciton in a bilayer system
as an electric dipole, we provide a general theory for the electric dipole
superconductivity, and derive the London-type and Ginzburg-Landau-type
equations for the electric dipole superconductors. By using these equations, we
discover the Meissner-type effect and the electric dipole current Josephson
effect. These effects can provide direct evidence for the formation of the
exciton superfluid state in bilayer systems and pave new ways to drive an
electric dipole current.Comment: 10 pages, 5 figures, 1 Supplementary Informatio
Assessment of Resident Physicians in Professionalism, Interpersonal and Communication Skills: a Multisource Feedback
Objective: To assess the internal validity and reliability of a multisource feedback (MSF) program by China Medical Board for resident physicians in China
Ginzburg-Landau-type theory of non-polarized spin superconductivity
Since the concept of spin superconductor was proposed, all the related
studies concentrate on spin-polarized case. Here, we generalize the study to
spin-non-polarized case. The free energy of non-polarized spin superconductor
is obtained, and the Ginzburg-Landau-type equations are derived by using the
variational method. These Ginzburg-Landau-type equations can be reduced to the
spin-polarized case when the spin direction is fixed. Moreover, the expressions
of super linear and angular spin currents inside the superconductor are
derived. We demonstrate that the electric field induced by super spin current
is equal to the one induced by equivalent charge obtained from the second
Ginzburg-Landau-type equation, which shows self-consistency of our theory. By
applying these Ginzburg-Landau-type equations, the effect of electric field on
the superconductor is also studied. These results will help us get a better
understanding of the spin superconductor and the related topics such as
Bose-Einstein condensate of magnons and spin superfluidity.Comment: 9 pages, 5 figure
Design and Synthesis of Novel Anticancer Peptide Nanoparticles
Cancer has now become a common disease affecting human health. Existing cancer treatment drugs can no longer meet the growing needs of cancer patients, and the emergence of anticancer drug resistance has exacerbated this phenomenon. By designing and synthesizing new anticancer peptide nanoparticles and studying their anticancer effects, new strategies for cancer treatment may be obtained. Novel anticancer peptides are synthesized by adding basic amino acids and solid-phase synthesis technology, and their structural information is determined by mass spectrometry. Nanoparticles of anticancer peptide were synthesized by nano-self-assembly technology. Two novel anticancer peptides exhibited anticancer activity, one of which was assembled into nanoparticles. The theoretical isoelectric points of the modified SZG3 and SZG5 are all greater than physiological pH, and will be positively charged under physiological conditions. The estimated half-life of SZG3 and SZG5 is significantly extended (30h), which is beneficial to increase the efficacy and reduce toxic and side effects. SZG3 and SZG5 have a good inhibitory effect on tumor cells and have low toxicity to normal cells.
Keywords: anticancer peptide, study, design, cancer, nanoparticles 
A Note on Hierarchy of Quantum Measurement Incompatibilities
The quantum measurement incompatibility is a distinctive feature of quantum
mechanics. We investigate the incompatibility of a set of general measurements
and classify the incompatibility by the hierarchy of compatibilities of its
subsets. By using the approach of adding noises to measurement operators we
present a complete classification of the incompatibility of a given measurement
assemblage with members. Detailed examples are given to the incompatibility
for unbiased qubit measurements based on semidefinite programm.Comment: 11pages,0 figure
Bell Inequalities Classifying Bi-separable Three-qubit States
We present a set of Bell inequalities that gives rise to a finer
classification of the entanglement for tripartite systems. These inequalities
distinguish three possible bi-separable entanglements for three-qubit states.
The three Bell operators we employed constitute an external sphere of the
separable cube.Comment: 8 page
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