493,858 research outputs found

### About "On certain incomplete statistics" by Lima et al

Lima et al recently claim that ({\em Chaos, Solitons & Fractals,}
2004;19:1005)the entropy for the incomplete statistics based on the
normalization$\sum_ip_i^q=1$ should be $S=-\sum_ip_i^{2q-1}\ln_qp_i$ instead
of$S=-\sum_ip_i^{q}\ln_qp_i$ initially proposed by Wang. We indicate here that
thisconclusion is a result of erroneous use of temperature definition for the
incompletestatistics

### Quantum CPU and Quantum Algorithm

Making use of an universal quantum network -- QCPU proposed by
me\upcite{My1}, it is obtained that the whole quantum network which can
implement some the known quantum algorithms including Deutsch algorithm,
quantum Fourier transformation, Shor's algorithm and Grover's algorithm.Comment: 8 pages, Revised Versio

### Spin and Orbital Splitting in Ferromagnetic Contacted Single Wall Carbon Nanotube Devices

We observed the coulomb blockade phenomena in ferromagnetic contacting single
wall semiconducting carbon nanotube devices. No obvious Coulomb peaks shift was
observed with existing only the Zeeman splitting at 4K. Combining with other
effects, the ferromagnetic leads prevent the orbital spin states splitting with
magnetic field up to 2 Tesla at 4K. With increasing magnetic field further,
both positive or negative coulomb peaks shift slopes are observed associating
with clockwise and anticlockwise orbital state splitting. The strongly
suppressed/enhanced of the conductance has been observed associating with the
magnetic field induced orbital states splitting/converging

### The energy spectrum symmetry of Heisenberg model in Fock space

We prove strictly that one dimension spin 1/2 Heisenberg model has a symmetry
of energy spectrum between its subspace $n$ and the subspace $L-n$ of the Fock
space. Our proof is completed by introducing two general quantum operations.
One is a flip operation of spin direction and another is a mirror reflection of
spin sites.Comment: Revising version, 7 preprint pages, no figures; Published version
contains some revisions in Languag

### Thermodynamics, phase transitions and Ruppeiner geometry for Einstein-dilaton Lifshitz black holes in the presence of Maxwell and Born-Infeld electrodynamics

In this paper, we first obtain the ($n+1$)-dimensional dilaton-Lifshitz black
hole (BH) solutions in the presence of Born-Infeld (BI) electrodynamics. We
find that there are two different solutions for $z=n+1$ and $z\neq n+1$ cases
($z$ is dynamical critical exponent). We show that the thermodynamics first law
is satisfied for both cases. Then, we turn to study different phase transitions
(PTs) for our BHs. We start with study of Hawking-Page PT for both linearly and
BI charged BHs. After that, we discuss the PTs inside the BHs. We present the
improved Davies quantities and prove that the PT points shown by them coincide
with Ruppeiner ones. We show that the zero temperature PTs are transitions on
radiance properties of BHs by using Landau-Lifshitz theory. Next, we turn to
study Ruppeiner geometry of linearly and BI charged BHs. For linearly charged
case, we show that there are no PT at finite temperature for the case $z\geq
2$. For $z<2$, it is found that the number of finite temperature PT points
depends on the value of BH charge and is not more than two. When we have two
finite temperature PT points, there are no thermally stable BH between these
two points and we have discontinues small/large BH PTs. As expected, for small
BHs, we observe finite magnitude for Ruppeiner invariant which shows the finite
correlation between possible BH molecules while for large BHs, the correlation
is very small. Finally, we study the Ruppeiner geometry and thermal stability
of BI charged Lifshtiz BHs for different values of $z$. We observe that small
BHs are thermally unstable in some situations. Also, the behavior of
correlation between possible BH molecules for large BHs is the same as linearly
charged case. In both linearly and BI charged cases, for some choices of
parameters, the BH systems behave like a Van der Waals gas near transition
point.Comment: V2: 23 pages (revtex format), 13 figures (except one, all include
subfigures), some references adde

### Escaping free-energy minima

We introduce a novel and powerful method for exploring the properties of the
multidimensional free energy surfaces of complex many-body systems by means of
a coarse-grained non-Markovian dynamics in the space defined by a few
collective coordinates.A characteristic feature of this dynamics is the
presence of a history-dependent potential term that, in time, fills the minima
in the free energy surface, allowing the efficient exploration and accurate
determination of the free energy surface as a function of the collective
coordinates. We demonstrate the usefulness of this approach in the case of the
dissociation of a NaCl molecule in water and in the study of the conformational
changes of a dialanine in solution.Comment: 3 figure

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