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Jian Zhou

Publications and source records attributed to Jian Zhou.

At least 217 records · Page 12Linked to original sources
arXiv2019

Sudakov suppression of the Balitsky-Kovchegov kernel

To sum high energy leading logarithms in a consistent way, one has to impose the strong ordering in both projectile rapidity and dense target rapidity simultaneously, which results in a kinematically improved Balitsky-Kovchegov(BK) equation. We find that beyond this strong ordering region, the important sub-leading double logarithms arise at high order due to the incomplete cancellation between real corrections and virtual corrections in a t-channel calculation. Based on this observation, we further argue that these double logarithms are the Sudakov type ones, and thus can be resummed into an exponential leading to a Sudakov suppressed BK equation.

hep-ph↗
arXiv2019

On Performance of Peer Review for Academic Journals: Analysis Based on Distributed Parallel System

A simulation model based on parallel systems is established, aiming to explore the relation between the number of submissions and the overall standard of academic journals within a similar discipline under peer review. The model can effectively simulate the submission, review, and acceptance behaviors of academic journals in a distributed manner. According to the simulation experiments, it could possibly happen that the overall standard of academic journals deteriorates due to excessive submissions.

cs.DL↗
arXiv2019

Grothendieck's Dessins d'Enfants in a Web of Dualities. II

We show that the spectral curve for Eynard-Orantin topological recursions satisfied by counting Grothendieck's dessins d'enfants are related to Narayana numbers. This suggests a connection of dessins to combinatorics of Coxeter groups, noncrossing partitions, free probability theory, and cluster algebras.

math-ph↗
arXiv2019

On Itzykson-Zuber Ansatz

We apply the renormalized coupling constants and Virasoro constraints to derive the Itzykson-Zuber Ansatz on the form of the free energy in topological 2D gravity. We also treat the topological 1D gravity and the Hermitian one-matrix models in the same fashion. Some uniform behaviors are discovered in this approach.

math-ph↗
arXiv2019

Grothendieck's Dessins d'Enfants in a Web of Dualities

In this paper we show that counting Grothendieck's dessins d'enfants is universal in the sense that some other enumerative problems are either special cases or directly related to it. Such results provide concrete examples that support a proposal made in the paper to study various dualities from the point of view of group actions on the moduli space of theories. Connections to differential equations of hypergeometric type can be made transparent from this approach, suggesting a connection to mirror symmetry.

math-ph↗
arXiv2019

Near-infrared optical properties and proposed phase-change usefulness of transition metal disulfides

The development of photonic integrated circuits would benefit from a wider selection of materials that can strongly-control near-infrared (NIR) light. Transition metal dichalcogenides (TMDs) have been explored extensively for visible spectrum opto-electronics, but the NIR properties of these layered materials have been less-studied. The measurement of optical constants is the foremost step to qualify TMDs for use in NIR photonics. Here we measure the complex optical constants for select sulfide TMDs (bulk crystals of MoS2, TiS2 and ZrS2) via spectroscopic ellipsometry in the visible-to-NIR range. Through Mueller matrix measurements and generalized ellipsometry, we explicitly measure the direction of the ordinary optical axis. We support our measurements with density functional theory (DFT) calculations, which agree with our measurements and predict giant birefringence. We further propose that TMDs could find use as photonic phase-change materials, by designing alloys that are thermodynamically adjacent to phase boundaries between competing crystal structures, to realize martensitic (i.e. displacive, order-order) switching.

cond-mat.mes-hall↗
arXiv2019

Strain Effects on the Mechanical Properties of Group-V Monolayers with Buckled Honeycomb Structures

Based on first-principles calculations, we study systematically the ideal tensile stress-strain relations of three monoatomic group-V monolayer two dimensional (2D) materials with buckled honeycomb lattices: blue phosphorene, arsenene, and antimonene. The ideal strengths and critical strains for these 2D materials are investigated under uniaxial and equibiaxial strains. It is found that the ideal strengths decrease significantly as the atomic number increases, while the critical strains change not so much. In particular, the ideal strength of antimonene along armchair direction is found to exceed Griffith strength limit. The distributions of charge density, buckling heights, bond lengths, and bond angles are also studied under different types of strains. It can be concluded that the critical strain is determined by the stretch and rotation of bonds simultaneously. Furthermore, the phonon dispersions, phonon instabilities, and failure mechanism of these materials under three types of strains are also calculated and explored.

physics.comp-ph↗
arXiv2019

Emergent Geometry of Matrix Models with Even Couplings

We show that to the modified GUE partition function with even coupling introduced by Dubrovin, Liu, Yang and Zhang, one can associate $n$-point correlation functions in arbitrary genera which satisfy Eynard-Orantin topological recursions. Furthermore, these $n$-point functions are related to intersection numbers on the Deligne-Mumford moduli spaces.

math-ph↗
arXiv2019

A Unified Approach to Holomorphic Anomaly Equations and Quantum Spectral Curves

We present a unified approach to holomorphic anomaly equations and some well-known quantum spectral curves. We develop a formalism of abstract quantum field theory based on the diagrammatics of the Deligne-Mumford moduli spaces $\overline{\mathcal M}_{g,n}$ and derive a quadratic recursion relation for the abstract free energies in terms of the edge-cutting operators. This abstract quantum field theory can be realized by various choices of a sequence of holomorphic functions or formal power series and suitable propagators, and the realized quantum field theory can be represented by formal Gaussian integrals. Various applications are given.

math-ph↗
arXiv2019

Battery selection for optimal grid-outage resilient photovoltaic and battery systems

The first and most important purpose of the current research work is to investigate the effects that different battery types have on the optimal configuration of photovoltaic (PV) and battery systems, from both economic and resilience perspectives. Many industry reports, as well as research papers, have already highlighted the crucial role that storage systems have in the coming years in the electricity sector, especially when combined with renewable energy systems (RES). Given the high cost of storage technologies, there is an urgent need for optimizing such integrated energy systems. In this paper, a simulation-based method is adopted and improved, in order to compare different battery types based on their characteristics by considering projected trends in the future. After the introduction of four different battery types, i.e. lead-acid, sodium sulphur, vanadium redox and lithium-ion, the mathematical model for the optimization problem is presented, along with the required explanations. Subsequently, a case study is described and the numerical assumptions are defined. Therein, our specific focus addresses the different values that the four battery types possess in three critical parameters, i.e. battery cost, efficiency and depth of discharge (DoD). Finally, results and discussion are provided in an illustrative and informative way. This model provides a useful guide for relevant future work in the area, and also serves as a baseline for more comprehensive methodologies regarding optimal sizing of photovoltaic and battery systems.

eess.SP↗
arXiv2019

Band Structure Engineering of Interfacial Semiconductors Based on Atomically Thin Lead Iodide Crystals

To explore new constituents in two-dimensional materials and to combine their best in van der Waals heterostructures, are in great demand as being unique platform to discover new physical phenomena and to design novel functionalities in interface-based devices. Herein, PbI2 crystals as thin as few-layers are first synthesized, particularly through a facile low-temperature solution approach with the crystals of large size, regular shape, different thicknesses and high-yields. As a prototypical demonstration of flexible band engineering of PbI2-based interfacial semiconductors, these PbI2 crystals are subsequently assembled with several transition metal dichalcogenide monolayers. The photoluminescence of MoS2 is strongly enhanced in MoS2/PbI2 stacks, while a dramatic photoluminescence quenching of WS2 and WSe2 is revealed in WS2/PbI2 and WSe2/PbI2 stacks. This is attributed to the effective heterojunction formation between PbI2 and these monolayers, but type I band alignment in MoS2/PbI2 stacks where fast-transferred charge carriers accumulate in MoS2 with high emission efficiency, and type II in WS2/PbI2 and WSe2/PbI2 stacks with separated electrons and holes suitable for light harvesting. Our results demonstrate that MoS2, WS2, WSe2 monolayers with very similar electronic structures themselves, show completely distinct light-matter interactions when interfacing with PbI2, providing unprecedent capabilities to engineer the device performance of two-dimensional heterostructures.

cond-mat.mes-hall↗
arXiv2018

Long-distance continuous-variable quantum key distribution using separable Gaussian states

Continuous-variable quantum key distribution (CVQKD) is considered to be an alternative to classical cryptography for secure communication. However, its transmission distance is restricted to metropolitan areas, given that it is affected by the channel excess noise and losses. In this paper, we present a scheme for implementing long-distance CVQKD using separable Gaussian states. This tunable QKD protocol requires separable Gaussian states, which are squeezed and displaced, along with the assistance of classical communication and available linear optics compoments. This protocol originates from the entanglement of one mode and the auxiliary mode used for distribution, which is first destroyed by local correlated noises and restored subsequently by the interference of the auxillary mode with the second distant separable correlated mode. The displacement matrix is organized by two six-dimensional vectors and is finally fixed by the separability of the tripartite system. The separability between the ancilla and Alice and Bob's system mitigates the enemy's eavesdropping, leading to tolerating higher excess noise and achieving longer transmission distance.

quant-ph↗
arXiv2018

Perceptual Visual Interactive Learning

Supervised learning methods are widely used in machine learning. However, the lack of labels in existing data limits the application of these technologies. Visual interactive learning (VIL) compared with computers can avoid semantic gap, and solve the labeling problem of small label quantity (SLQ) samples in a groundbreaking way. In order to fully understand the importance of VIL to the interaction process, we re-summarize the interactive learning related algorithms (e.g. clustering, classification, retrieval etc.) from the perspective of VIL. Note that, perception and cognition are two main visual processes of VIL. On this basis, we propose a perceptual visual interactive learning (PVIL) framework, which adopts gestalt principle to design interaction strategy and multi-dimensionality reduction (MDR) to optimize the process of visualization. The advantage of PVIL framework is that it combines computer's sensitivity of detailed features and human's overall understanding of global tasks. Experimental results validate that the framework is superior to traditional computer labeling methods (such as label propagation) in both accuracy and efficiency, which achieves significant classification results on dense distribution and sparse classes dataset.

cs.CV↗
arXiv2018

Fat and Thin Emergent Geometries of Hermitian One-Matrix Models

We use genus zero free energy functions of Hermitian matrix models to define spectral curves and their special deformations. They are special plane curves defined by formal power series with integral coefficients generalizing the Catalan numbers. This is done in two different versions, depending on two different genus expansions, and these two versions are in some sense dual to each other.

math-ph↗
arXiv2018

Genus Expansions of Hermitian One-Matrix Models: Fat Graphs vs. Thin Graphs

We consider two different genus expansions of the free energy functions of Hermitian one-matrix models, one using fat graphs, one using ordinary graphs (thin graphs). Some structural results are first proved for the thin version of genus expansion using renormalized coupling constants, and then applied to the fat version.

math-ph↗
arXiv2018

Hermitian One-Matrix Model and KP Hierarchy

The partition functions of Hermitian one-matrix models are known to be tau-functions of the KP hierarchy. In this paper we explicitly compute the elements in Sato grassmannian these tau-functions correspond to, and use them to compute the $n$-point functions of Hermitian one-matrix model.

math-ph↗