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Valentin I. Zakharov - One of the best experts on this subject based on the ideXlab platform.

  • unruh effect universality emergent conical geometry from Density Operator
    Journal of High Energy Physics, 2020
    Co-Authors: Valentin I. Zakharov, Georgy Y. Prokhorov, O V Teryaev
    Abstract:

    The Unruh effect has been investigated from the point of view of the quantum statistical Zubarev Density Operator in space with the Minkowski metric. Quantum corrections of the fourth order in acceleration to the energy-momentum tensor of real and complex scalar fields, and Dirac field are calculated. Both massless and massive fields are considered. The method for regularization of discovered infrared divergences for scalar fields is proposed. The calculated corrections make it possible to substantiate the Unruh effect from the point of view of the statistical approach, and to explicitly show its universality for various quantum field theories of massless and massive fields. The obtained results exactly coincide with the ones obtained earlier by calculation of the vacuum aver- age of energy-momentum tensor in a space with a conical singularity. Thus, the duality of two methods for describing an accelerated medium is substantiated. One may also speak about the emergence of geometry with conical singularity from thermodynamics. In particular, the polynomiality of the energy-momentum tensor and the absence of higher-order corrections in acceleration can be explicitly demonstrated.

  • Calculation of Acceleration Effects Using the Zubarev Density Operator
    Particles, 2020
    Co-Authors: Georgy Y. Prokhorov, Oleg Teryaev, Valentin I. Zakharov
    Abstract:

    The relativistic form of the Zubarev Density Operator can be used to study quantum effects associated with acceleration of the medium. In particular, it was recently shown that the calculation of perturbative corrections in acceleration based on the Zubarev Density Operator makes it possible to show the existence of the Unruh effect. In this paper, we present the details of the calculation of quantum correlators arising in the fourth order of the perturbation theory needed to demonstrate the Unruh effect. Expressions for the quantum corrections for massive fermions are also obtained.

  • Calculation of acceleration effects using the Zubarev Density Operator
    arXiv: High Energy Physics - Theory, 2019
    Co-Authors: Georgy Y. Prokhorov, Oleg Teryaev, Valentin I. Zakharov
    Abstract:

    The relativistic form of the Zubarev Density Operator can be used to study quantum effects associated with acceleration of the medium. In particular, it was recently shown that the calculation of perturbative corrections in acceleration based on the Zubarev Density Operator makes it possible to show the existence of Unruh effect. In this paper, we present the details of the calculation of quantum correlators arising in the fourth order of the perturbation theory needed to demonstrate the Unruh effect. Expressions for the quantum corrections for massive fermions are also obtained.

  • unruh effect for fermions from the zubarev Density Operator
    Physical Review D, 2019
    Co-Authors: Georgy Y. Prokhorov, O V Teryaev, Valentin I. Zakharov
    Abstract:

    Using the Zubarev quantum-statistical Density Operator, we calculated the corrections to the energy-momentum tensor of a massless fermion gas associated with acceleration. It is shown that when fourth-order corrections are taken into account, the energy-momentum tensor in the laboratory frame is equal to zero at a proper temperature measured by a comoving observer equal to Unruh temperature. Consequently, the Minkowski vacuum is visible to the accelerated observer as a medium filled with a heat bath of particles with the Unruh temperature, which is the essence of the Unruh effect.

  • Effects of rotation and acceleration in the axial current: Density Operator vs Wigner function
    Journal of High Energy Physics, 2019
    Co-Authors: George Prokhorov, Oleg Teryaev, Valentin I. Zakharov
    Abstract:

    The hydrodynamic coefficients in the axial current are calculated on the basis of the equilibrium quantum statistical Density Operator in the third order of perturbation theory in thermal vorticity tensor both for the case of massive and massless fermions. The coefficients obtained describe third-order corrections to the Chiral Vortical Effect and include the contribution from local acceleration. We show that the methods of the Wigner function and the statistical Density Operator lead to the same result for an axial current in describing effects associated only with vorticity when the local acceleration is zero, but differ in describing mixed effects for which both acceleration and vorticity are significant simultaneously.

Sungwoo Hwang - One of the best experts on this subject based on the ideXlab platform.

  • lorentz covariant reduced Density Operator theory for relativistic quantum information processing
    Physical Review A, 2003
    Co-Authors: Doyeol Ahn, Hyukjae Lee, Sungwoo Hwang
    Abstract:

    In this paper, we derived a Lorentz-covariant quantum Liouville equation for the Density Operator which describes the relativistic-quantum-information processing from Tomonaga-Schwinger equation and an exact formal solution for the reduced Density Operator is obtained using the projector Operator technique and the functional calculus. When all the members of the family of the hypersurfaces become flat hyperplanes, it is shown that our results agree with those of the nonrelativistic case, which is valid only in some specified reference frame. To show that our formulation can be applied to practical problems, we derived the polarization of the vacuum in quantum electrodynamics up to the second order. The formulation presented in this work is general and could be applied to related fields such as quantum electrodynamics and relativistic statistical mechanics.

  • time convolutionless reduced Density Operator theory of a noisy quantum channel two bit quantum gate for quantum information processing
    Physical Review A, 2000
    Co-Authors: Doyeol Ahn, K Kimm, Sungwoo Hwang
    Abstract:

    An exact reduced-Density-Operator for the output quantum states in time-convolutionless form was derived by solving the quantum Liouville equation which governs the dynamics of a noisy quantum channel by using a projection Operator method and both advanced and retarded propagators in time. The formalism developed in this work is general enough to model a noisy quantum channel provided specific forms of the Hamiltonians for the system, reservoir, and the mutual interaction between the system and the reservoir are given. Then we apply the formulation to model a two-bit quantum gate composed of coupled spin systems in which the Heisenberg coupling is controlled by the tunneling barrier between neighboring quantum dots. Gate characteristics, including the entropy, fidelity, and the purity, are calculated numerically for both mixed and entangled initial states.

Georgy Y. Prokhorov - One of the best experts on this subject based on the ideXlab platform.

  • unruh effect universality emergent conical geometry from Density Operator
    Journal of High Energy Physics, 2020
    Co-Authors: Valentin I. Zakharov, Georgy Y. Prokhorov, O V Teryaev
    Abstract:

    The Unruh effect has been investigated from the point of view of the quantum statistical Zubarev Density Operator in space with the Minkowski metric. Quantum corrections of the fourth order in acceleration to the energy-momentum tensor of real and complex scalar fields, and Dirac field are calculated. Both massless and massive fields are considered. The method for regularization of discovered infrared divergences for scalar fields is proposed. The calculated corrections make it possible to substantiate the Unruh effect from the point of view of the statistical approach, and to explicitly show its universality for various quantum field theories of massless and massive fields. The obtained results exactly coincide with the ones obtained earlier by calculation of the vacuum aver- age of energy-momentum tensor in a space with a conical singularity. Thus, the duality of two methods for describing an accelerated medium is substantiated. One may also speak about the emergence of geometry with conical singularity from thermodynamics. In particular, the polynomiality of the energy-momentum tensor and the absence of higher-order corrections in acceleration can be explicitly demonstrated.

  • Calculation of Acceleration Effects Using the Zubarev Density Operator
    Particles, 2020
    Co-Authors: Georgy Y. Prokhorov, Oleg Teryaev, Valentin I. Zakharov
    Abstract:

    The relativistic form of the Zubarev Density Operator can be used to study quantum effects associated with acceleration of the medium. In particular, it was recently shown that the calculation of perturbative corrections in acceleration based on the Zubarev Density Operator makes it possible to show the existence of the Unruh effect. In this paper, we present the details of the calculation of quantum correlators arising in the fourth order of the perturbation theory needed to demonstrate the Unruh effect. Expressions for the quantum corrections for massive fermions are also obtained.

  • Calculation of acceleration effects using the Zubarev Density Operator
    arXiv: High Energy Physics - Theory, 2019
    Co-Authors: Georgy Y. Prokhorov, Oleg Teryaev, Valentin I. Zakharov
    Abstract:

    The relativistic form of the Zubarev Density Operator can be used to study quantum effects associated with acceleration of the medium. In particular, it was recently shown that the calculation of perturbative corrections in acceleration based on the Zubarev Density Operator makes it possible to show the existence of Unruh effect. In this paper, we present the details of the calculation of quantum correlators arising in the fourth order of the perturbation theory needed to demonstrate the Unruh effect. Expressions for the quantum corrections for massive fermions are also obtained.

  • unruh effect for fermions from the zubarev Density Operator
    Physical Review D, 2019
    Co-Authors: Georgy Y. Prokhorov, O V Teryaev, Valentin I. Zakharov
    Abstract:

    Using the Zubarev quantum-statistical Density Operator, we calculated the corrections to the energy-momentum tensor of a massless fermion gas associated with acceleration. It is shown that when fourth-order corrections are taken into account, the energy-momentum tensor in the laboratory frame is equal to zero at a proper temperature measured by a comoving observer equal to Unruh temperature. Consequently, the Minkowski vacuum is visible to the accelerated observer as a medium filled with a heat bath of particles with the Unruh temperature, which is the essence of the Unruh effect.

Jing-ling Chen - One of the best experts on this subject based on the ideXlab platform.

O V Teryaev - One of the best experts on this subject based on the ideXlab platform.

  • unruh effect universality emergent conical geometry from Density Operator
    Journal of High Energy Physics, 2020
    Co-Authors: Valentin I. Zakharov, Georgy Y. Prokhorov, O V Teryaev
    Abstract:

    The Unruh effect has been investigated from the point of view of the quantum statistical Zubarev Density Operator in space with the Minkowski metric. Quantum corrections of the fourth order in acceleration to the energy-momentum tensor of real and complex scalar fields, and Dirac field are calculated. Both massless and massive fields are considered. The method for regularization of discovered infrared divergences for scalar fields is proposed. The calculated corrections make it possible to substantiate the Unruh effect from the point of view of the statistical approach, and to explicitly show its universality for various quantum field theories of massless and massive fields. The obtained results exactly coincide with the ones obtained earlier by calculation of the vacuum aver- age of energy-momentum tensor in a space with a conical singularity. Thus, the duality of two methods for describing an accelerated medium is substantiated. One may also speak about the emergence of geometry with conical singularity from thermodynamics. In particular, the polynomiality of the energy-momentum tensor and the absence of higher-order corrections in acceleration can be explicitly demonstrated.

  • unruh effect for fermions from the zubarev Density Operator
    Physical Review D, 2019
    Co-Authors: Georgy Y. Prokhorov, O V Teryaev, Valentin I. Zakharov
    Abstract:

    Using the Zubarev quantum-statistical Density Operator, we calculated the corrections to the energy-momentum tensor of a massless fermion gas associated with acceleration. It is shown that when fourth-order corrections are taken into account, the energy-momentum tensor in the laboratory frame is equal to zero at a proper temperature measured by a comoving observer equal to Unruh temperature. Consequently, the Minkowski vacuum is visible to the accelerated observer as a medium filled with a heat bath of particles with the Unruh temperature, which is the essence of the Unruh effect.