2,007 research outputs found
Trace inequalities on a generalized Wigner-Yanase skew information
We introduce a generalized Wigner-Yanase skew information and then derive the
trace inequality related to the uncertainty relation. This inequality is a
non-trivial generalization of the uncertainty relation derived by S.Luo for the
quantum uncertainty quantity excluding the classical mixure. In addition,
several trace inequalities on our generalized Wigner-Yanase skew information
are argued
Some remarks on the coherent-state variational approach to nonlinear boson models
The mean-field pictures based on the standard time-dependent variational
approach have widely been used in the study of nonlinear many-boson systems
such as the Bose-Hubbard model. The mean-field schemes relevant to
Gutzwiller-like trial states , number-preserving states and
Glauber-like trial states are compared to evidence the specific
properties of such schemes. After deriving the Hamiltonian picture relevant to
from that based on , the latter is shown to exhibit a Poisson
algebra equipped with a Weyl-Heisenberg subalgebra which preludes to the
-based picture. Then states are shown to be a superposition of -boson states and the similarities/differences of the -based and
-based pictures are discussed. Finally, after proving that the simple,
symmetric state indeed corresponds to a SU(M) coherent state, a dual
version of states and in terms of momentum-mode operators is
discussed together with some applications.Comment: 16 page
Printable Thermoelectric Device
We have fabricated a printed flexible thermoelectric generator using composite of Bi2Te3 and PEDOT:PSS. The nano-structured thermoelectric thin film was made by printing method and the paste for printing was prepared by mixing nano-particles of Bi2Te3, PEDOT:PSS and polyamic acid as a additives. The non-dimensional figure of merit was 0.2 for p-type composite thin film at room temperature due to the low thermal conductivity. The interfacial thermal resistance between Bi2Te3 and PEDOT:PSS was measured to understand the low effective thermal conductivity of the printed thermoelectric composite. The measured organic-inorganic interfacial thermal resistance is in the order of 10−7 (m2centerdotK)/W which is about 10 times higher than the inorganic-inorganic interfacial thermal resistance. The extremely low thermal conductivity of the printed thermoelectric materials can be explained by high interfacial resistance between inorganic-organic materials.18th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS 2018), 4–7 December 2018, Daytona Beach, Florida, US
First-principles study on the origin of large thermopower in hole-doped LaRhO3 and CuRhO2
Based on first-principles calculations, we study the origin of the large
thermopower in Ni-doped LaRhO3 and Mg-doped CuRhO2. We calculate the band
structure and construct the maximally localized Wannier functions from which a
tight binding Hamiltonian is obtained. The Seebeck coefficient is calculated
within the Boltzmann's equation approach using this effective Hamiltonian. For
LaRhO3, we find that the Seebeck coefficient remains nearly constant within a
large hole concentration range, which is consistent with the experimental
observation. For CuRhO2, the overall temperature dependence of the calculated
Seebeck coefficient is in excellent agreement with the experiment. The origin
of the large thermopower is discussed.Comment: 7 pages, to be published J. Phys.: Cond. Matt., Proc. QSD 200
Fundamental properties of Tsallis relative entropy
Fundamental properties for the Tsallis relative entropy in both classical and
quantum systems are studied. As one of our main results, we give the parametric
extension of the trace inequality between the quantum relative entropy and the
minus of the trace of the relative operator entropy given by Hiai and Petz. The
monotonicity of the quantum Tsallis relative entropy for the trace preserving
completely positive linear map is also shown without the assumption that the
density operators are invertible.
The generalized Tsallis relative entropy is defined and its subadditivity is
shown by its joint convexity. Moreover, the generalized Peierls-Bogoliubov
inequality is also proven
Reduction techniques of the back gate effect in the SOI Pixel Detector
We have fabricated monolithic pixel sensors in 0.2 μm Silicon-On-Insulator (SOI) CMOS technology, consisting of a thick sensor layer and a thin circuit layer with an insulating buried-oxide, which has many advantages. However, it has been found that the applied electric field in the sensor layer also affects the transistor operation in the adjacent circuit layer. This limits the applicable sensor bias well below the full depletion voltage. To overcome this, we performed a TCAD simulation and added an additional p-well (buried pwell) in the SOI process. Designs and preliminary results are presented
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