Event date:
Sep 23 2022 11:30 am

Role of initial correlations in open quantum systems

Mr. Ali Raza Mirza, PhD Student, Physics Department, LUMS
SBASSE 10-302
Open quantum systems are a subject of immense interest and importance, as they hold great potential in implementing modern quantum technologies. In the study of dynamics, it is common practice to ignore initial system-environment correlations to make the problem easier to tackle. However, this approximation fails to explain physical insights accurately in a strong system-environment coupling regime. We solve an exactly solvable model of a qubit interacting with a bunch of qubits (spin environment), first with and then without initial correlations, all for any system-environment coupling strengths. We show that the effect of initial correlations is important to consider in weak coupling and even more important at low temperatures and strong coupling. We also observe that the effect of the system state preparation need not be significant at low temperatures with high coupling strength. We extend our study to investigate the dynamics of entanglement between two qubits interacting with a common spin environment, Once again we obtain promising results that emphasize the importance of initial correlations under various practical situations of interest.

Ali Raza Mirza is a senior Ph.D. student in the Physics department at LUMS. In 2010, He is awarded a Gold Medal from "The University of Gujrat" in BSc annual examination. He has done a master's and M.Phil. from QAU Islamabad and GCU Lahore respectively. He has worked as a visiting lecturer at Riphah International University for a semester. In 2021, during his Ph.D., he has been awarded a scholarship namely the 'International Research Support Initiative Program (IRSIP) by the Higher Education Commission of Pakistan (HEC) and worked as a visiting researcher at the University of Manchester. Ali Raza Mirza does calligraphy in his leisure time.