Quantum Information Lab Physics Faculty
HomeResearchPeoplePublicationsTalks & PresentationsTeachingLinks
 
Research

The laboratory runs currently several scientific projects aimed at the foundations of quantum information science (the theories of quantum measurement and entanglement, design and analysis of quantum cryptographic protocols, atoms dynamics in optical dipole trap, etc.), applications of quantum theory to modeling quantum interference phenomena in multilevel atoms interacting with optical and magnetic fields (dark resonance spectroscopy), and exploring applications of laser coherent control of molecular chiral states.

Short description of these projects and annual laboratory reports are given below.

Foundations of Quantum Information Theory

Abstract

This project on the foundations of quantum information processing, a new emerging interdisciplinary field of science, aims to develop new theories and methods for processing information at the quantum level. We currently work on developing theories of quantum measurement (i.e., entangling measurement and exact mathematical description of other types of quantum measurements), quantum information (coherent and unselected information), design and quantum-information-analysis of quantum cryptographic protocols, and other applications of quantum information, for example to the atomic dynamics in an optical dipole trap and to the chiral states of simple chiral molecules that could be considered as a qubit embody. The project is run in collaboration with experimental and theoretical groups (see Collaborators) under the INTAS-funded project on quantum information processing. [MORE DETAILS]

Publications

  1. B.A.Grishanin, V.N.Zadkov, "Measurement and physical content of quantum information", J. of Communications Technology and Electronics 47(9), 1029–1046 (2002). [REVIEW] [PDF];
    LALNL e-print quant-ph/0210190 (2002).
  2. I.V.Bargatin, B.A.Grishanin, V.N.Zadkov, "Entangled quantum states of atomic systems", Physics-Uspekhi 44(6), 597-616 (2001). [REVIEW] [PDF].
    И. В. Баргатин, Б. А. Гришанин, and В. Н. Задков, “Запутанные квантовые состояния атомных систем”, УФН 171, 625–647 (2001). (In Russian) [REVIEW] [PDF]

Sponsors

Russian Foundation for Basic Research, grant No. 1-02-16311
INTAS, grant INFO 00-479
Russian Ministry of Science and Technologies

Collaborators

Prof. Dieter Meschede, Institute of Applied Physics, University of Bonn, Germany
Prof. Eugene Polzik, Department of Physics and Astronomy, University of Aarhus, Denmark
Prof. Victor Balykin, Istitute of Spectroscopy, Russian Academy of Sciences, Russia
Dr. Dmitriy Kupriyanov, Dept. of Theoretical Physics, St. Petersburg State Technical Univ., Russia


Dark Resonances Spectroscopy in Multilevel Atoms

Abstract

Three-level atomic systems compared to their two-level counterparts display a much broader range of new effects as a result of coherence among the states induced by the radiation and quantum interference. Among them the coherent population trapping (CPT) is the most intriguing phenomenon. It is most conspicuous for the lambda-transition between two closely spaced long lived levels optically coupled to a third distant short lived level by two continuous coherent radiation fields. In absorption spectra coherent superposition of closely spaced levels leads to a very narrow dip of induced transparency or, equivalently, a nonabsorbing dark resonance when resonance fluorescence is observed. Theory of CPT-phenomenon is well understood in the frame of three-level model, however it significantly complicates for the case of multilevel systems and analytical calculations in most cases are impossible. Enriched energetic structure of multilevel atoms results also in essential modification of the resonance dependencies on the radiation parameters. In this project, we develop a theoretical model of CPT in multilevel atoms and apply it to the real experimental data received for different atoms and various conditions (among which applied magnetic field is one of the most essential factors). We work here in close contact with the experimental groups. [MORE DETAILS]

Publications

  1. Yu.V.Vladimirova, B.A.Grishanin, V.N.Zadkov, N.N.Kolachevskii, A.V.Akimov, N.A.Kisilev, S.I.Kanorskii, "Spectroscopy of coherent dark resonances in multilevel atoms for the example of samarium vapor", J. of Theor. and Exp. Physics 96(4), 629-642 (2003). [PDF]
    Ю.В.Владимирова, Б.А.Гришанин, В.Н.Задков, Н.Н.Колачевский, А.В.Акимов, Н.А.Кисилев, С.И.Канорский, "Спектроскопия когерентных темных резонансов в многоуровневых атомах на примере паров самария", ЖЭТФ, 123(4), 710-725(2003). [PS]
  2. J. V. Vladimirova, B. A. Grishanin, V. N. Zadkov, N. N. Kolachevsky, A.V. Akimov, N.A. Kiselev, V.N. Sorokin, and S.I. Kanorski, “Spectroscopy of coherent dark resonances in samarium”, In: SPIE Procs. Vol. 4749, pp.147–156 (2002). [PDF].

Sponsors

Russian Foundation for Basic Research, grant No. 1-02-16311
INTAS, grant INFO 00-479
Russian Ministry of Science and Technologies

Collaborators

Dr. Sergei Kanorski, Lebedev Physical Institute, Moscow, Russia
Dr. Robert Wynands, Departement de Physique, Universite de Fribourg, Switzerland

Laser Coherent Control of Molecular Chiral States

Abstract

Preferential synthesis of a required type of enantiomers with light from a racemic mixture of chiral molecules is recognized to be of great importance in chemistry, pharmaceutics, and medicine. Yet, no successful experimental realization of a preferential laser synthesis scheme from a racemic solution has been demonstrated. Basically, there are two totally different schemes for preferential synthesis. One of them is based on preferential selection of left- or right-handed enantiomers from a racemic mixture with no change in the nuclear configurations of the molecules. Another scheme is based on photoinduced synthesis of a required type of enantiomers from the other ones using methods of coherent control. Such synthesis is called laser distillation and, as has been shown first by Shapiro and Brumer [Phys. Rev. Lett. 84, 1669 (2000)] and then by us [1,2], may be quite efficient for practical applications by contrast with the preferential selection schemes that turned out to be inefficient. In this project, we study how to use coherent control for manipulating molecular chiral states, starting with hydrogen peroxide molecule (H2O2) and its isotopomer (HOOD), the simplest chiral molecules. Another application of molecular chiral states as the qubit embodies is also interesting for the quantum information processing. [MORE DETAILS]

Publications

  1. S.S.Bychkov, B.A.Grishanin, V.N.Zadkov, "Laser synthesis of chiral molecules in isotropic racemic media", J. of Theor. and Exp. Physics 93(1), 24-32 (2001).
    С. С. Бычков, Б. А. Гришанин, В. Н. Задков, “Лазерный синтез хиральных молекул в изотропных рацемических средах”, ЖЭТФ 120, 31–40 (2001). [In Russian] [PDF]
  2. S. S. Bychkov, B. A. Grishanin, V. N. Zadkov and H. Takahashi, “Laser coherent control of molecular chiral states via entanglement of the rotational and torsional degrees of freedom”, J. Raman Spectr. 33(11–12), 962–973 (2002). [PDF]

Sponsors

Russian Foundation for Basic Research, grant No. 02-03-32200
INTAS, grant INFO 00-479
Waseda University International Exchange Fund (under Exchange Program with Moscow State University)

Collaborators

Prof. Hiroaki Takahashi, Department of Chemistry, Waseda University, Japan

Short Annual Laboratory Reports (in Russian, PDF)

| 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 |

 

Home | Research | People | Publications | Talks | Teaching | Contacts | Links
This document was last modified on May 24, 2012 at 16:41:58
© 2018 Quantum Information Laboratory. All rights reserved.