The phase diagrams and phase transitions of a typical bilayer fractional quantum Hall (QH) system with filling factor ν = 2/3 at the layer balanced point are investigated theoretically by finite size exact-diagonaliz...The phase diagrams and phase transitions of a typical bilayer fractional quantum Hall (QH) system with filling factor ν = 2/3 at the layer balanced point are investigated theoretically by finite size exact-diagonalization calculations and an exactly solvable model. We find some basic features essentially different from the bilayer integer QH systems at ν = 2, reflecting the special characteristics of the fractional QH systems. The degeneracy of the ground states occurs depending on the difference between intralayer and interlayer Coulomb energies, when interlayer tunneling energy (ΔSAS) gets close to zero. The continuous transitions of the finite size systems between the spin-polarized and spin-unpolarized phases are determined by the competition between the Zeeman energy (ΔZ) and the electron Coulomb energy, and are almost not affected by ΔSAS.展开更多
In this treatise we stress the analogy between strongly interacting many-body systems and elementary particle physics in the context of Quantum Field Theory (QFT). The common denominator between these two branches of ...In this treatise we stress the analogy between strongly interacting many-body systems and elementary particle physics in the context of Quantum Field Theory (QFT). The common denominator between these two branches of theoretical physics is the Green’s function or propagator, which is the key for solving specific problems. Here we are concentrating on the vacuum, its excitations and its interaction with electron and photon fields.展开更多
If the Planck length is chosen as the natural length scale of the Universe, the Penrose-Carter diagram associated with the classical gravitational collapse of a thin spherical shell of massless matter reveals, beyond ...If the Planck length is chosen as the natural length scale of the Universe, the Penrose-Carter diagram associated with the classical gravitational collapse of a thin spherical shell of massless matter reveals, beyond and in agreement with the claimed non locality of the horizon, a quantum nature of the whole process.展开更多
Optoelectronic applications require the development of new fluorescent and efficient luminescent materials, free of toxicity, low in cost, and easy to produce. In this way the synthesis of zinc-oxide (ZnO) quantum dot...Optoelectronic applications require the development of new fluorescent and efficient luminescent materials, free of toxicity, low in cost, and easy to produce. In this way the synthesis of zinc-oxide (ZnO) quantum dots (QDs) has recently received special attention due to their good optical, electrical and chemical properties with low production costs and blue light emission. In this work ZnO QDs were successfully doped with europium in order to obtain a tunable emission luminescence from blue emission of ZnO to red emission of europium as a function of wavelength excitation. Results show an efficient blue to red tuning when the excitation wavelength was changed from 317 nm to 395 nm, respectively. This opens the possibility of having new optical devices to produce different color emission using the same material.展开更多
The study of protein folding is fundamental and important in the multidisciplinary field because a diversity of diseases,like Alzheimer’s and Parkinson’s are relevant to protein misfolding.The current thermodynamic ...The study of protein folding is fundamental and important in the multidisciplinary field because a diversity of diseases,like Alzheimer’s and Parkinson’s are relevant to protein misfolding.The current thermodynamic and geometric approaches only phenomenologically describe but do not provide a mechanistic understanding of the competition between correct folding and misfolding.Here we present a model to understand the misfolding behavior.Considering the influence of dissipative strength for all possible sequences and comparing the folding time toward different compact structures,we obtain a phase diagram of the dissipative quantum phase transition that enables us to model the behavior.We also investigate how a perturbation in the Hamiltonian affects the transition point,which motivates us to explore possible manual interventions.Our results indicate that the manual intervention may be effective for some specific sequence but not for everyone.This approach is expected to lay a foundation for further studies on manual intervention in protein misfolding.展开更多
文摘The phase diagrams and phase transitions of a typical bilayer fractional quantum Hall (QH) system with filling factor ν = 2/3 at the layer balanced point are investigated theoretically by finite size exact-diagonalization calculations and an exactly solvable model. We find some basic features essentially different from the bilayer integer QH systems at ν = 2, reflecting the special characteristics of the fractional QH systems. The degeneracy of the ground states occurs depending on the difference between intralayer and interlayer Coulomb energies, when interlayer tunneling energy (ΔSAS) gets close to zero. The continuous transitions of the finite size systems between the spin-polarized and spin-unpolarized phases are determined by the competition between the Zeeman energy (ΔZ) and the electron Coulomb energy, and are almost not affected by ΔSAS.
文摘In this treatise we stress the analogy between strongly interacting many-body systems and elementary particle physics in the context of Quantum Field Theory (QFT). The common denominator between these two branches of theoretical physics is the Green’s function or propagator, which is the key for solving specific problems. Here we are concentrating on the vacuum, its excitations and its interaction with electron and photon fields.
文摘If the Planck length is chosen as the natural length scale of the Universe, the Penrose-Carter diagram associated with the classical gravitational collapse of a thin spherical shell of massless matter reveals, beyond and in agreement with the claimed non locality of the horizon, a quantum nature of the whole process.
文摘Optoelectronic applications require the development of new fluorescent and efficient luminescent materials, free of toxicity, low in cost, and easy to produce. In this way the synthesis of zinc-oxide (ZnO) quantum dots (QDs) has recently received special attention due to their good optical, electrical and chemical properties with low production costs and blue light emission. In this work ZnO QDs were successfully doped with europium in order to obtain a tunable emission luminescence from blue emission of ZnO to red emission of europium as a function of wavelength excitation. Results show an efficient blue to red tuning when the excitation wavelength was changed from 317 nm to 395 nm, respectively. This opens the possibility of having new optical devices to produce different color emission using the same material.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0304304)the National Natural Science Foundation of China(Grant No.11935012)。
文摘The study of protein folding is fundamental and important in the multidisciplinary field because a diversity of diseases,like Alzheimer’s and Parkinson’s are relevant to protein misfolding.The current thermodynamic and geometric approaches only phenomenologically describe but do not provide a mechanistic understanding of the competition between correct folding and misfolding.Here we present a model to understand the misfolding behavior.Considering the influence of dissipative strength for all possible sequences and comparing the folding time toward different compact structures,we obtain a phase diagram of the dissipative quantum phase transition that enables us to model the behavior.We also investigate how a perturbation in the Hamiltonian affects the transition point,which motivates us to explore possible manual interventions.Our results indicate that the manual intervention may be effective for some specific sequence but not for everyone.This approach is expected to lay a foundation for further studies on manual intervention in protein misfolding.
