2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/213108In this report, we examine the decoherence of a spin qubits system coupled to counted spin chain with a $1/r^2$ interaction by using influence functional. We also examine the time evolution of density matrix numerically when environment is Gaussian noise.9 pagesMesoscale and Nanoscale PhysicsStatistical MechanicsQuantum Physicstext