Brajesh Kumar Mani

Department of Physics, Indian Institute of

Technology Delhi, Hauz Khas, New Delhi 110016

E-mail: bkmani[at]physics.iitd.ac.in

Brief Bio-sketch:

Dr. Mani is an Assistant Professor in the Department of Physics, IIT Delhi. Before joining IIT Delhi in Dec 2015, Dr. Mani worked at the University of South Florida as a Postdoctoral Research Associate from Jan 2012 to Dec 2015. He did his PhD from the Physical Research Laboratory, Ahmedabad in Jan 2011. The current research area of Dr. Mani is computational condensed matter physics, and his expertise encapsulates the development and use of computational tools to probe physics and corresponding technological applications of atomic and many-atomic complex systems.

FINITE TEMPERATURE PROPERTIES SIMULATIONS IN PEROVSKITES BULK AND NANOSTRUCTURES

The condensed matter systems often form a many-body system for which the exact solution is impractical or even impossible some time. The recent advances in Density Functional Theory (DFT) and based methods have contributed immensely in theoretical predictions of a plethora of physical properties in a variety of condensed matter systems. There are, however, two important limitations with DFT, which impose a serious restriction on the use of DFT to the simulation of the properties which evolves strongly with temperature. First, being the ground state theory, it does not provide accurate descriptions of the properties at finite temperatures. Second, it cannot handle the systems with more than few hundred atoms. One way to mitigate this problem and trace the properties at finite temperatures, is to use the force-field based Molecular Dynamics and/or Monte Carlo simulations. The parameters in the force-field are derived from the DFT and based calculations [1, 2]. In this talk, with the help of the example of a perovskite (anti)ferroelectric oxide, I shall provide a brief but systematic illustration of how to simulate the properties at finite temperatures. I shall also share some important results from my simulations [3-5].

References

[1] R. D. King-Smith and D. Vanderbilt, Phys. Rev. B 49, 5828 (1994).

[2] W. Zhong, D. Vanderbilt, and K. M. Rabe, Phys. Rev. Lett. 73, 1861 (1994).

[3] B. K. Mani, C.-M. Chang, and I. Ponomareva, Phys. Rev. B 88,064306 (2013).

[4] B. K. Mani, S. Lisenkov, and I. Ponomareva, Phys. Rev. B 91, 134112 (2015).

[5] B. K. Mani, C.-M. Chang, S. Lisenkov, and I. Ponomareva, Phys. Rev. Lett. 115, 097101 (2015).