arXiv subjects
Publications and source records attributed to Chetan Kotabage.
The most common way to find gravitational acceleration, g, in a laboratory is to use a simple pendulum and a clock. Alternately, g can be calculated by measuring time and distance for a free fall. Since the time of free fall in a laboratory is short, there are challenges in measuring the short period. In this article, a low cost technique to measure the time for a free fall using a discharging RC circuit is discussed.
Plank's constant is a fundamental constant in Physical sciences and Millikan received Noble prize for obtaining it experimentally in 1923. As the technology of solid state electronic devices developed, an experiment was designed and adapted to determine the Plank's constant using LED. Herrmann and Schätzle questioned the validity of this experiment on the basis of the diode equation and their approach was further discussed by Morehouse. In this article, the validity of this experiment is revisited.
Fermi energy, which is a theoretical concept, has been explored in an experiment for a copper wire. In this article, scientific validity of this experiment is discussed. A correct method to determine Fermi energy is also discussed.
We develop a strong-disorder renormalization group to study quantum phase transitions with continuous O$(N)$ symmetry order parameters under the influence of both quenched disorder and dissipation. For Ohmic dissipation, as realized in Hertz' theory of the itinerant antiferromagnetic transition or in the superconductor-metal transition in nanowires, we find the transition to be governed by an exotic infinite-randomness fixed point in the same universality class as the (dissipationless) random transverse-field Ising model. We determine the critical behavior and calculate key observables at the transition and in the associated quantum Griffiths phase. We also briefly discuss the cases of superohmic and subohmic dissipations.
We study the effects of dissipation on a disordered quantum phase transition with O$(N)$ order parameter symmetry by applying a strong-disorder renormalization group to the Landau-Ginzburg-Wilson field theory of the problem. We find that Ohmic dissipation results in a non-perturbative infinite-randomness critical point with unconventional activated dynamical scaling while superohmic damping leads to conventional behavior. We discuss applications to the superconductor-metal transition in nanowires and to Hertz' theory of the itinerant antiferromagnetic transition.