Chintalpati Umashankar Shastry
About
Chintalpati Umashankar Shastry is a Post-Graduate Research Student under the supervision of Dr Andrea Rocco and Dr Marian Florescu, in the department of physics at the University of Surrey. He completed his undergraduate degree in mechanical engineering from Motilal Nehru National Institute of Technology (Allahabad). Umashankar studied at University of Surrey to get Masters of Science in physics. His area of interest is in open quantum system and its application in quantum thermodynamics. Currently, he is working on quantum thermodynamical framework for understanding off-equilibrium properties of living systems. In addition to this project, he is undertaking another project where he is trying to apply the renormalisation group approach to open quantum system.
University roles and responsibilities
- Post-Graduate Research Student (PhD) (2023-Present)
- Associate Intern at Department of Physics (2022-2023)
My qualifications
ResearchResearch interests
Open quantum system and its application in Quantum Thermodynamics.
Research projects
Quantum Thermodynamical Framework For Understanding Off-Equilibrium Properties of Living SystemsIn this project he aims to investigate how life maintains its highly ordered, low-entropy, far-from-equilibrium dynamical state. He will adopt open quantum systems theory and quantum thermodynamics to make predictions that may be used to assess the underlying classical and quantum dynamics of physical and biological and systems. He will focus on systems with memory effects and identify deviations from standard thermodynamics, which may require reformulations of entropy functions and fluctuation-dissipation relations. Analysis of these deviations is expected to shed light on the fundamental differences between living and non-living systems.
Renormalisation Group approach to open quantum systemsCurrently, he is undertaking another project where he is working in the group of Dr Andrea Rocco to apply the renormalisation group approach to open quantum systems and obtain an exact renormalisation group equation in the Non-Markovian limit. In this project he is trying to use Wilson’s renormalization group techniques to get the correction terms due to the quantum fluctuations at large frequency cut-off in the Fourier modes of the effective action of the system, this can be calculated by the shell mode integration of the Wilsonian effective action. He is trying to derive the two point Wegner-Houghton equation for the Super-propagator and then translate this finding to know the change in the dynamics of the system's reduced density matrix.
Dirac EquationHe worked on solving the Dirac equation for hydrogen atom in finite basis expansion as his MSc Dissertation. This project was supervised by Dr Paul Stevenson. In this work, matrix representation of Dirac Hamiltonian was obtained in a finite set basis spinors. In principle any infinite basis set can be used to obtain a matrix representation of the Hamiltonian of the system, however, if the basis set are not kinetically balanced, then the so called spurious energy states fill the energy spectrum. Two methods were developed, namely basis expansion method and Variational method. In basis expansion method the inner product of kinetically balanced Dirac basis spinors were taken with Dirac Hamiltonian to get the matrix elements, while in the Variational method large component was expanded in terms of orthonormal basis functions while the small component was expanded in kinetically balanced basis functions. Both methods give rise to the spurious energy states, however, variational method shows less spurious states than basis expansion method for the given number of basis functions (or spinors in the case of basis expansion method). Variational method is slower and the convergence of largest positive energy eigenvalue to the theoretical ground state energy is slower than basis expansion method.
Research interests
Open quantum system and its application in Quantum Thermodynamics.
Research projects
In this project he aims to investigate how life maintains its highly ordered, low-entropy, far-from-equilibrium dynamical state. He will adopt open quantum systems theory and quantum thermodynamics to make predictions that may be used to assess the underlying classical and quantum dynamics of physical and biological and systems. He will focus on systems with memory effects and identify deviations from standard thermodynamics, which may require reformulations of entropy functions and fluctuation-dissipation relations. Analysis of these deviations is expected to shed light on the fundamental differences between living and non-living systems.
Currently, he is undertaking another project where he is working in the group of Dr Andrea Rocco to apply the renormalisation group approach to open quantum systems and obtain an exact renormalisation group equation in the Non-Markovian limit. In this project he is trying to use Wilson’s renormalization group techniques to get the correction terms due to the quantum fluctuations at large frequency cut-off in the Fourier modes of the effective action of the system, this can be calculated by the shell mode integration of the Wilsonian effective action. He is trying to derive the two point Wegner-Houghton equation for the Super-propagator and then translate this finding to know the change in the dynamics of the system's reduced density matrix.
He worked on solving the Dirac equation for hydrogen atom in finite basis expansion as his MSc Dissertation. This project was supervised by Dr Paul Stevenson. In this work, matrix representation of Dirac Hamiltonian was obtained in a finite set basis spinors. In principle any infinite basis set can be used to obtain a matrix representation of the Hamiltonian of the system, however, if the basis set are not kinetically balanced, then the so called spurious energy states fill the energy spectrum. Two methods were developed, namely basis expansion method and Variational method. In basis expansion method the inner product of kinetically balanced Dirac basis spinors were taken with Dirac Hamiltonian to get the matrix elements, while in the Variational method large component was expanded in terms of orthonormal basis functions while the small component was expanded in kinetically balanced basis functions. Both methods give rise to the spurious energy states, however, variational method shows less spurious states than basis expansion method for the given number of basis functions (or spinors in the case of basis expansion method). Variational method is slower and the convergence of largest positive energy eigenvalue to the theoretical ground state energy is slower than basis expansion method.