Department of Particle Physics and Astrophysics

You are here

Shmuel Gurvitz

Professor Emeritus
Tel:+972-8-934-2332
Location:Edna and K.B. Weissman Building of Physical Sciences, Room 236

Current Research Interests

Quantum measurement and Decoherence; Quantum transport in mesoscopic and molecular systems; Quantum Mechanics in Biology; Multi-dimensional tunneling

The main topic of my current research is a quantum system interacting with the macro- scopic environment (open quantum system). In particular, I am interesting in transition between quantum and classical description and quantum measurement, where the macro- scopic (mesoscopic) detectors are considered as a part of the environment. For a realization of this program I derived new Master equations from the many-body Schro¨dinger equation, when the environment is far from equilibrium (see a review paper [1]). These equations contained an additional variable related to the environment. It allowed us to study simul- taneously the quantum system and the environment (detector), and therefore to trace out dynamics of the measurement process.

The method has been recently applied for study the continuous Schro¨dinger evolution of the entire system, including detector, versus continuous non-selective measurements via von Neumann projections (quantum trajectory). Assuming that the both methods must produce the same outcome, we arrived to universal relation between decorerence rate, generated by the detector and the measurement time [2]. This result may indicate on a fundamental role of information in quantum evolution.

Recently, our approach has been also applied for a description of exciton dynamics in the light harvesting complex of the photo-synthetic systems. The resulting Master equations account the multi-exciton states, as well as the charge-separation, fluorescence and photo- absorption. Although these effects take place on very different time-scales, we demonstrated that their inclusion is necessary for a consistent description of the exciton dynamics. We applied our results to evaluate energy (exciton) and fluorescence current and  effciency of the energy transfer as a function of sunlight intensity [3,4].

At present time I am developing a new “single-particle approach” to quantum transport in open systems, which is free from the non-equilibrium restrictions of our previous Master equations approach [1]. The new approach has been successfully applied for description of quantum transport in time-dependent potential [5] and under fluctuating environment [6].

 

  1. Shmuel Gurvitz, Wave-function approach to Master equations for quantum transport and measurement, Front. Phys. 12, 120303 (2017).

  2. Shmuel Gurvitz, Does the measurement take place when nobody observes it?, Fortschritte der Physik - Progress of Physics, 65, 1600065 (2017).
  3. Shmuel Gurvitz, Alexander I. Nesterov and Gennady P. Berman, Multi-Scale Exci- ton and Electron Transfer in Multi-Level Donor-Acceptor System, Journal of Physics A:Mathematical and Theoretical, 50, 365601 (2017).
  4. Shmuel Gurvitz, Gennady P. Berman and Richard T. Sayre, Multiscale Multiexciton Cyclic Dynamics in Light Harvesting Complex, arXiv:1706.01958.
  5. Shmuel Gurvitz, Single-electron approach for  time-dependent electron transport, Physica Scripta, T165, 014013 (2015).
  6. Shmuel Gurvitz, Amnon Aharony and Ora Entin-Wohlman, Temporal evolution of resonant  transmission  under  telegraph noise, Phys. Rev. B94, 075437 (2016).