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Sukhbir Singh

Publications and source records attributed to Sukhbir Singh.

3 recordsLinked to original sources

Toward the Ultimate Limit: Elemental Metals in One Dimension

Low-dimensional materials exhibit extraordinary properties that make them promising candidates for advanced technologies. Although they have been investigated extensively, most of the research has focused on layered two-dimensional (2D) materials. Here, inspired by recent advances in atomically thin metallenes, we further reduce dimensionality and use density-functional theory simulations to study the geometry, energetics, elasticity, and electronic structure of 40 non-magnetic one-dimensional (1D) atomic chains of elemental metals. We find that nearly all chains have a buckled ground state, nine chains are distorted, and three chains---Cd, Hg, and Sr---are semiconducting with an electronic gap. We also find that transition metals retain a substantial fraction of their 3D bulk cohesive energy even in 1D chains. We assessed chains' dynamical stabilities by molecular dynamics simulations and found that 26 of them are thermodynamically stable at 100 K. Finally, we performed chain pulling simulations to investigate the straightening dynamics of selected stable chains. Given that experimental techniques have recently reached the 1D-chain limit, our systematic study provides a foundation and timely guide to accelerating synthesis and characterization of these materials.

cond-mat.mtrl-sci

Estimation of MIDAS Regressions with Errors-in-the-Variables

In this paper, a Mixed Data Sampling (MIDAS) model is studied when both low and high frequency variables are contaminated with measurement error. It is shown that the profile likelihood estimator becomes inconsistent in the presence of measurement error. Using the corrected score approach along with profile likelihood approach, a consistent estimator for parameters of MIDAS Measurement Error model is proposed. Small and large sample properties of the estimator are examined by performing a monte carlo simulation study and considering the effect of sample size, number of lags and profiling parameter.

stat.ME

Atomically Thin Metallenes at the Edge

Atomically thin metallenes are a new family of materials representing the ultimate limit of a thin free-electron gas for novel applications. Although metallene research has gained traction, limited attention has been paid to the properties of their ubiquitous edges. Here, we use density-functional theory simulations to investigate various edges of Mg, Cu, Y, Au, and Pb metallenes with hexagonal and buckled honeycomb lattices. Investigating relaxations, energies, stresses, and electronic structures at the edge, we find that some properties have clear trends while others are sensitive to both element and lattice type. Given that edge properties are fundamental to metallene stability and interactions in lateral heterostructures, their detailed understanding will help guide the development of metallene synthesis and applications.

cond-mat.mtrl-sci