arXiv subjects

J. S. Kang

Publications and source records attributed to J. S. Kang.

3 recordsLinked to original sources

arXiv2019

Experimental evidence of the non-diffusive avalanche-like electron heat transport events and their dynamical interaction with the shear flow structure

We present experimental observations suggesting that the non-diffusive avalanche-like events are a prevalent and universal process of the electron turbulent heat transport in tokamak core plasmas. They are observed in the low confinement mode and the weak internal transport barrier tokamak plasmas in the absence of magnetohydrodynamic instabilities. In addition, the electron temperature profile corrugation, which indicates the existence of the $E \times B$ shear flow layers, is clearly demonstrated as well as their dynamical interaction with the avalanche-like events. The measured width of the profile corrugation is around $45ρ_i$, which implies the mesoscale nature of the structure.

physics.plasm-ph↗

arXiv2009

A Study of the Branching Ratio of H ->cc_bar at a Future e+e- Linear Collider

We carried out a feasibility study on the measurement of the branching ratio of H -> cc_bar at a future e+e- linear collider. We used the topological vertex reconstructing algorithm for accumulating secondary vertex information and the neural network for optimizing c quark selection. With an assumption of a light Higgs mass of 120 GeV/c^2, we estimated the statistical error of Br(H -> cc_bar) to be 20.1% or 25.7% depending on the number of vertex detector layers at the center-of-mass energy of 250 GeV and the intergrated luminosity of 500 fb^-1.

hep-ex↗

arXiv2004

Spin singlet-triplet transition in a Si-based two-electron double quantum dot molecule

We report a successful measurement of the magnetic field-induced spin singlet-triplet transition in silicon-based coupled dot systems. Our specific experimental scheme incorporates a lateral gate-controlled Coulomb-blockaded structure in Si to meet the proposed scheme of Loss and DiVincenzo [1], and a non-equilibrium single-electron tunneling technique to probe the fine energy splitting between the spin singlet and triplet, which varies as a function of applying magnetic fields and interdot coupling constant. Our results, exhibiting the singlet-triplet crossing at a magnetic field for various interdot coupling constants, are in agreement with the theoretical predictions, and give the first experimental demonstration of the possible spin swapping occurring in the coupled double dot systems with magnetic field. *Electronic address: jungchoi@chungbuk.ac.kr [1] D. Loss and D. P. DiVincenzo, Phys. Rev. A 57, 120 (1998).

cond-mat.mes-hall↗