Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

We show that bipartite entanglement in an one-dimensional quantum spin model undergoing time evolution due to local Markovian environments can be frozen over time. We demonstrate this by using a number of paradigmatic quantum spin models including the anisotropic XY model in the presence of a uniform and an alternating transverse magnetic field (ATXY), the XXZ model, the XYZ model, and the J1-J2 model involving the next-nearest-neighbor interactions. We show that the length of the freezing interval, for a chosen pair of nearest-neighbor spins, may remain independent of the length of the spin chain, for example, in paramagnetic phases of the ATXY model, indicating a scale invariance. Freezing of entanglement is found to be robust against a change in the environment temperature, the presence of disorder in the system, and whether the noise is dissipative or not dissipative. Moreover, we connect the freezing of entanglement with the propagation of information through a quantum many-body system, as considered in the Lieb-Robinson theorem. We demonstrate that the variation of the freezing duration exhibits a quadratic behavior against the distance of the nearest-neighbor spin pair from the noise source, obtained from exact numerical simulations, in contrast to the linear one as predicted by the Lieb-Robinson theorem. © 2018 American Physical Society.

World University root node

Department of Physics

Fulltext

Physical Review A

Scale-invariant freezing of entanglement

There exist zero-temperature states in quantum many-body systems that are fully factorized, thereby possessing vanishing entanglement, and hence being of no use as resource in quantum information processing tasks. Such states can become useful for quantum protocols when the temperature of the system is increased, and when the system is allowed to evolve under either the influence of an external environment, or a closed unitary evolution driven by its own Hamiltonian due to a sudden change in the system parameters. Using the one-dimensional anisotropic XY model in a uniform and an alternating transverse magnetic field, we show that entanglement of the thermal states, corresponding to the factorization points in the space of the system parameters, revives once or twice with increasing temperature. We also study the closed unitary evolution of the quantum spin chain driven out of equilibrium when the external magnetic fields are turned off, and show that considerable entanglement is generated during the dynamics, when the initial state has vanishing entanglement. Interestingly, we find that creation of entanglement for a pair of spins is possible when the system is made open to an external heat bath, interacting with the system through that spin-pair via a repetitive quantum interaction. © 2018 American Physical Society.

Emergence of entanglement with temperature and time in factorization-surface states

Department of Mechanical Engineering

Cryogenics

Prediction of vapour-liquid and vapour-liquid-liquid equilibria of nitrogen-hydrocarbon mixtures used in JT refrigerators

We propose both monolithic and partitioned approach to solve conjugate heat transfer in an immersed boundary framework for complex geometries. The present framework is based on the staggered/non-staggered finite volume framework for incompressible flows which is extended to handle conjugate heat transfer. The key difference in the monolithic framework is that only a single hybrid momentum equation for normal momentum and single hybrid energy equation for temperature are solved simultaneously for both fluid and solid domains. However, in partitioned approach the energy equation is solved in each sub domain and temperature of both domains are coupled using suitable boundary conditions. The equations are discretized using a second-order accurate spatial and temporal scheme, that uses three point backward differencing for time discretisation and high-resolution schemes for convective discretisation, while central differencing is adopted for the viscous terms. The resulting discretized non-linear system of equations are solved using the Newton-Krylov approach. The momentum field at the cell centroids is then reconstructed using a defect-correction algorithm. The energy conservation equation is discretized similar to the collocated framework, with a second-order convection scheme for the convective terms and implicit Euler time stepping. These equations are linearized by considering the velocity field at the latest available time step, and the resulting linear system of equations are solved using SAAMG preconditioned GMRES solver using the LiS library. The effect of immersed solids are accounted for in the governing equation using a solid fraction approach. The investigations are be carried out for conjugate heat transfer with a backward-facing flow at different ratios of solid to fluid thermal diffusivities. Studies show that both monolithic and partitioned approaches can successfully simulate conjugate heat transfer with a backward-facing flow although the former shows a faster convergence to steady state solution. © 2018 by the authors of the abstracts.

International Conference on Computational Methods for Thermal Problems

A comparison between monolithic and partitioned approach for conjugate heat transfer in an immersed boundary framework

Efficiency of fiber reinforcements to ensure the sealing efficiency of the landfill cap soil barriers so as to isolate the waste from the environment was demonstrated in the present study. Evaluation of hydraulic conductivity of soil barrier materials with different types of fibers, fiber dosage and fiber lengths are very important to ensure the sealing efficiency of the fiber reinforced soil barriers. An attempt was made to evaluate the hydraulic conductivity of the soil barrier material at a known effective stress using a flexible wall permeameter. Soil samples of 100 mm diameter and 100 mm height were prepared and tested in the present study. In all the cases, the hydraulic conductivity test phase was started after the completion of initialisation, saturation and isotropic consolidation phases of the soil samples. In the present study, seventeen (17) hydraulic conductivity tests were conducted on two different soil types for studying the influence of fiber content, fiber length and fiber type on the hydraulic conductivity of fiber reinforced soil. The fiber content, f used were 0.25%, 0.50% and 0.75% and the fiber lengths, l were 30 mm, 60 mm and 90 mm. Two types of fibers namely polyester (PET) fibers and polypropylene tape (PP-T) fibers were used for hydraulic conductivity tests. The repeatability of test results was also demonstrated. As the fiber content and fiber length were increased, initially there was a marginal decrease in hydraulic conductivity of the soil and thereafter marginally increased. Short fibers and low fiber contents were found to have greater influence in reducing the hydraulic conductivity of the soil and the variation was found to depend on the soil type also. Even with long fibers, the hydraulic conductivity of selected barrier material remained within the permissible limit required for a barrier material. The hydraulic conductivity of PP-T fiber reinforced soil is more, compared to hydraulic conductivity of PET fiber reinforced soil at all the fiber contents varied in the present study. The use of Scanning Electron Microscopy (SEM) is also attempted for the interpretation of the results. © 2017 Elsevier Ltd

Department of Civil Engineering

Geotextiles and Geomembranes

Hydraulic conductivity behaviour of soil blended with geofiber inclusions

The well-known Sensitivity Conjecture regarding combinatorial complexity measures on Boolean functions states that for any Boolean function (Formula presented), block sensitivity of f is polynomially related to sensitivity of f (denoted by s(f)). From the complexity theory side, the Xor Log-Rank Conjecture states that for any Boolean function, (Formula presented) the communication complexity of a related function (Formula presented), (defined as (Formula presented)) is bounded by polynomial in logarithm of the sparsity of f (the number of non-zero Fourier coefficients for f, denoted by sparsity(f). Both the conjectures play a central role in the domains in which they are studied. A recent result of Lin and Zhang (2017) implies that to confirm the above two conjectures it suffices to upper bound alternation of f (denoted alt(f)) for all Boolean functions f by polynomial in s(f) and logarithm of sparsity(f), respectively. In this context, we show the following results: We show that there exists a family of Boolean functions for which alt(f) is at least exponential in s(f) and alt(f) is at least exponential in log sparsity(f). Enroute to the proof, we also show an exponential gap between alt(f) and the decision tree complexity of f, which might be of independent interest.As our main result, we show that, despite the above exponential gap between alt(f) and logsparsity(f), the Xor Log-Rank Conjecture is true for functions with the alternation upper bounded by poly(log n). It is easy to observe that the Sensitivity Conjecture is also true for this class of functions.The starting point for the above result is the observation (derived from Lin and Zhang (2017)) that for any Boolean function f, (Formula presented) where deg(f) and (Formula presented) are the degrees of f over R and F2. We give two further applications of this bound: (1) We show that Boolean functions with bounded alternation have high sparsity (Formula presented), thus partially answering a question of Kulkarni and Santha (2013). (2) We observe that the above relation improves the upper bound for influence to (Formula presented) improving Guo and Komargodski (2017). © Springer International Publishing AG 2018.

Department of Computer Science and Engineering

Communications in Computer and Information Science

Alternation, sparsity and sensitivity: Combinatorial bounds and exponential gaps

APS March Meeting Abstracts 2018, S14.

Extremely large magnetoresistance and Kohler's rule in PdSn4: a comprehensive study.

We consider the problem of link scheduling in multihop wireless networks subject to interference constraints. We consider a graph-based representation of wireless networks where scheduled links adhere to the $K$-hop link interference model. For this scheduling problem, we develop an asynchronous and distributed greedy heuristic. Furthermore, we show that this distributed heuristic computes the exact same schedule as the well-known centralized greedy link scheduling algorithm. © 1967-2012 IEEE.

IEEE Transactions on Vehicular Technology

Asynchronous Distributed Greedy Link Scheduling in Multihop Wireless Networks

Wireless and Social Networks: Some Challenges and Insights

The microscopic formula for the degeneracy of BMPV black hole microstates contains a series of exponentially suppressed corrections to the leading Bekenstein Hawking expression. We identify saddle points of the quantum entropy function for the BMPV black hole which are natural counterparts to these corrections and discuss the matching of leading and next-to-leading terms from the microscopic and macroscopic sides in a limit where the black hole charges are large. © 2018, The Author(s).