Engineering anomalous Floquet Majorana modes and their time evolution in helical Shiba chain

We theoretically explore the Floquet generation of Majorana end modes~(MEMs) (both regular $0$- and anomalous $\pi$-modes) implementing a periodic sinusoidal modulation in chemical potential in an experimentally feasible setup based on one-dimensional chain of magnetic impurity atoms having spin spiral configuration fabricated on the surface of most common bulk $s$-wave superconductor. We obtain a rich phase diagram in the parameter space, highlighting the possibility of generating multiple $0$-/$\pi$-MEMs localized at the end of the chain. We also study the real-time evolution of these emergent MEMs, especially when they start to appear in the time domain. These MEMs are topologically characterized by employing the dynamical winding number. We also discuss the possible experimental parameters in connection to our model. Our work paves the way to realize the Floquet MEMs in a magnet-superconductor heterostructure.Comment: 7.5 Pages + 5 PDF figures (Main Text), 4 Pages + 3 PDF figures (Supplementary Material), Comments are welcom

Assessment of ecosystem services of rice farms in eastern India

Authors acknowledge the financial help provided by Ministry of Earth Sciences, Govt. of India and also thank Director General, Indian Council of Agricultural Research (ICAR) and Director, ICAR-National Rice Research Institute (NRRI) for giving all the necessary help in executing the work. The help provided by Odisha state officials in carrying out the survey work is gratefully acknowledged. This study is a part of the project entitled “Delivering food security on limited land (DEVIL; Belmont Forum / FACCE-JPI via NERC: NE/M021327/1).Peer reviewedPublisher PD

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Anomaly in the dynamical quantum phase transition in a non-Hermitian system with extended gapless phases

The dynamical quantum phase transitions (DQPTs) and the associated winding numbers have been extensively studied in the context Hermitian system. We consider the non-Hermitian analog of p-wave superconductor, supporting Hermitian gapless phase with complex hopping, in presence of on-site or superconducting loss term. This allows us to investigate the effect of non-Hermitian gapless phases on the DQPTs in addition to the Hermitian gapless phases. Our findings indicate that contour analysis of the underlying Hamiltonian, enclosing the origin and/or exceptional points, can predict the occurrences of DQPTs except the quench within the gapless phases. For the Hermitian case with initial and final Hamiltonians both being Hermitian, we find nonmonotonic integer jump for the winding number as the hallmark signature of the gapless phase there. For the hybrid case with initial and final Hamiltonians being Hermitian and non-Hermitian respectively, winding number exhibits integer spike in addition to the nonmonotonic integer jumps. For the non-Hermitian case with initial and final Hamiltonians both being non-Hermitian, the winding number show half-integer jumps for lossy superconductivity that does not have any Hermitian analog. On the other hand, the integer jumps in winding number is observed for lossy chemical potential. We understand our findings by connecting them with the profile of Fisher zeros and number of exceptional points and/or origin

Anomaly in dynamical quantum phase transition in non-Hermitian system with extended gapless phases

The dynamical quantum phase transitions (DQPTs) and the associated winding numbers have been extensively studied in the context Hermitian system. We consider the non-Hermitian analogue of $p$-wave superconductor, supporting Hermitian gapless phase with complex hopping, in presence of on-site or superconducting loss term. This allows us to investigate the effect of non-Hermitian gapless phases on the DQPTs in addition to the Hermitian gapless phases. Our findings indicate that contour analysis of the underlying Hamiltonian, enclosing the origin and/or exceptional points, can predict the occurrences of DQPTs except the quench within the gapless phases. For the Hermitian case with initial and final Hamiltonians both being Hermitian, we find non-monotonic integer jump for the winding number as the hallmark signature of the gapless phase there. For the hybrid case with initial and final Hamiltonians being Hermitian and non-Hermitian respectively, winding number exhibits integer spike in addition to the non-monotonic integer jumps. For the non-Hermitian case with initial and final Hamiltonians both being non-Hermitian, the winding number show half-integer jumps for lossy superconcuctivity that does not have any Hermitian analogue. On the other hand, the integer jumps in winding number is observed for lossy chemical potential. We understand our findings by connecting them with the profile of Fisher zeros and number of exceptional points and/or origin.Comment: 12 pages, 17 figure

Finite-temperature dynamical quantum phase transition in a non-Hermitian system

We investigate the interplay between non-Hermiticity and finite temperature in the context of a mixed-state dynamical quantum phase transition (MSDQPT). We consider a p-wave superconductor model, encompassing complex hopping and non-Hermiticity, that can lead to gapless phases in addition to gapped phases, to examine the MSDQPT and winding number via the intraphase quench. We find that the MSDQPT is always present irrespective of the gap structure of the underlying phase; however, the profile of Fisher zeros changes between the above phases. Such occurrences of MSDQPT are in contrast to the zero-temperature case in which a DQPT does not take place for the gapped phase. Surprisingly, the half-integer jumps in winding number at zero temperature are washed away for finite temperature in the gapless phase. We study the evolution of the minimum time required by the system to experience MSDQPT with the inverse temperature such that gapped and gapless phases can be differentiated. Our study indicates that the minimum time shows monotonic (nonmonotonic) behavior for the gapped (gapless) phase

Semi-analytical finite element analysis of a strip footing on an elastic reinforced soil

A plane strain elastic interaction analysis of a strip footing resting on a reinforced soil bed has been made by using a combined analytical and finite element method (FEM). In this approach the stiffness matrix for the footing has been obtained using the FEM, For the reinforced soil bed (halfplane) the stiffness matrix has been obtained using an analytical solution. For the latter, the reinforced zone has been idealised as (i) an equivalent orthotropic infinite strip (composite approach) and (ii) a multilayered system (discrete approach). In the analysis, the interface between the strip footing and reinforced halfplane has been assumed as (i) frictionless and (ii) fully bonded. The contact pressure distribution and the settlement reduction have been given for different depths of footing and scheme of reinforcement in soil. The load-deformation behaviour of the reinforced soil obtained using the above modelling has been compared with some available analytical and model test results. The equivalent orthotropic approach proposed in this paper is easy to program and is shown to predict the reinforcing effects reasonably well

Bending analysis of a finite beam on a reinforced halfplane

This paper deals with an experimental study, using the photoelastic method, on the bending analysis of a centrally loaded finite free-free beam resting on a partly reinforced (horizontally) elastic halfplane. In the experimental study the interface between the beam and partly reinforced halfplane has been made both frictionless and fully bonded. An experimental-numerical hybrid method, developed earlier by the authors has been used to determine the contact pressure distribution. The contact pressure distribution thus obtained has been compared with the results obtained using an analytical-numerical procedure in which two different modellings have been used for the reinforced region viz., (i) equivalent orthotropic (composite approach); and (ii) layered system (discrete approach). Results of contact pressure distribution as well as bending stress distribution in the beam have been presented for several cases. The experimental procedure presented here is easy to apply to such complex practical problems and could be of interest to design engineers

Eco-evolutionary games for harvesting self-renewing common resource: effect of growing harvester population

The tragedy of the commons (TOCs) is a ubiquitous social dilemma witnessed in interactions between a population of living entities and shared resources available to them: the individuals in the population tend to selfishly overexploit a common resource as it is arguably the rational choice, or in case of non-human beings, it may be an evolutionarily uninvadable action. How to avert the TOC is a significant problem related to the conservation of resources. It is not hard to envisage situations where the resource could be self-renewing and the size of the population may be dependent on the state of the resource through the fractions of the population employing different exploitation rates. If the self-renewal rate of the resource lies between the maximum and the minimum exploitation rates, it is not a priori obvious under what conditions the TOC can be averted. In this paper, we address this question analytically and numerically using the setup of an evolutionary game theoretical replicator equation that models the Darwinian tenet of natural selection. Through the replicator equation, while we investigate how a population of replicators exploit the shared resource, the latter’s dynamical feedback on the former is also not ignored. We also present a transparent bottom-up derivation of the game-resource feedback model to facilitate future studies on the stochastic effects on the findings presented herein