A. Komnik

Publications (6)2.55 Total impact

• Article: Entanglement between nitrogen vacancy spins in diamond controlled by a nanomechanical resonator

  L. Chotorlishvili, D. Sander, A. Sukhov, V. Dugaev, V. R. Vieira, A. Komnik, J. Berakdar
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  ABSTRACT: We suggest a new type of nano-electromechanical resonator, the functionality of which is based on a magnetic field induced deflection of an appropriate cantilever that oscillates between nitrogen vacancy (NV) spins in daimond. Specifically, we consider a Si(100) cantilever coated with a thin magnetic Ni film. Magnetoelastic stress and magnetic-field induced torque are utilized to induce a controlled cantilever deflection. It is shown that, depending on the value of the system parameters, the induced asymmetry of the cantilever deflection substantially modifies the characteristics of the system. In particular, the coupling strength between the NV spins and the degree of entanglement can be controlled through magnetoelastic stress and magnetic-field induced torque effects. Our theoretical proposal can be implemented experimentally with the potential of increasing several times the coupling strength between the NV spins as compared to the maximal coupling strength reported before in P. Rabl, et al. Phys. Rev. B 79, 041302(R) (2009).
  01/2013;
• Article: Spin-orbital phase synchronization in the magnetic field-driven electron dynamics in a double-well potential.

  L Chotorlishvili, Z Toklikishvili, A Komnik, J Berakdar
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  ABSTRACT: We study the dynamics of an electron confined in a one-dimensional double-well potential in the presence of driving external magnetic fields. The orbital motion of the electron is coupled to the spin dynamics by spin-orbit interaction of the Dresselhaus type. We derive an effective time-dependent model Hamiltonian for the orbital motion of the electron and obtain a condition for synchronization of the orbital and the spin dynamics. We find an analytical expression for the Arnold 'tongue' and propose an experimental scheme for realizing the proposed synchronization.
  Journal of Physics Condensed Matter 05/2012; 24(25):255302. · 2.55 Impact Factor
• Source

  Available from: ArXiv

  Article: Chaotic spin-dependent electron dynamics in a field-driven double dot potential

  L. Chotorlishvili, Z. Toklikishvili, A. Komnik, J. Berakdar
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  ABSTRACT: We study the nonlinear classical dynamics of an electron confined in a double dot potential and subjected to a spin-orbit coupling and a constant external magnetic field. It is shown that due to the spin orbit coupling, the energy can be transferred from the spin to the orbital motion. This naturally heats up the orbital motion which, due to the presence of the separatrix line in the phase space of the system, results in a motion of the electron between the dots. It is shown that depending on the strength of the spin orbit coupling and the energy of the system, the electronic orbital motion undergoes a transition from the regular to the chaotic regime.
  10/2011;
• Source

  Available from: ArXiv

  Article: Spin-orbital phase synchronization in the magnetic field-driven electron dynamics in a double quantum dot

  L. Chotorlishvili, E. Ya. Sherman, Z. Toklikishvili, A. Komnik, J. Berakdar
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  ABSTRACT: We study the dynamics of an electron confined in a one-dimensional double quantum dot in the presence of driving external magnetic fields. The orbital motion of the electron is coupled to the spin dynamics by spin orbit interaction of the Dresselhaus type. We derive an effective time-dependent Hamiltonian model for the orbital motion of the electron and obtain a synchronization condition between the orbital and the spin dynamics. From this model we deduce an analytical expression for the Arnold tongue and propose an experimental scheme for realizing the synchronization of the orbital and spin dynamics.
  10/2011;
• Source

  Available from: Giorgi Mchedlishvili

  Article: Nonlinear dynamics of two coupled nano-electromechanical resonators

  L. Chotorlishvili, A. Ugulava, G. Mchedlishvili, A. Komnik, S. Wimberger, J. Berakdar
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  ABSTRACT: As a model of coupled nano-electromechanical resonantors we study two nonlinear driven oscillators with an arbitrary coupling strength between them. Analytical expressions are derived for the oscillation amplitudes as a function of the driving frequency and for the energy transfer rate between the two oscillators. The nonlinear restoring forces induce the expected nonlinear resonance structures in the amplitude-frequency characteristics with asymmetric resonance peaks. The corresponding multistable behavior is shown to be an efficient tool to control the energy transfer arising from the sensitive response to small changes in the driving frequency. Our results imply that the nonlinear response can be exploited to design precise sensors for mass or force detection experiments based on nano-electromechanical resonators.
  06/2011;
• Source

  Available from: ArXiv

  Article: Chaotic dynamics and spin correlation functions in a chain of nanomagnets

  L. Chotorlishvili, Z. Toklikishvili, A. Komnik, J. Berakdar
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  ABSTRACT: We study a chain of coupled nanomagnets in a classical approximation. We show that the infinitely long chain of coupled nanomagnets can be equivalently mapped onto an effective one-dimensional Hamiltonian with a fictitious time-dependent perturbation. We establish a connection between the dynamical characteristics of the classical system and spin correlation time. The decay rate for the spin correlation functions turns out to depend logarithmically on the maximal Lyapunov exponent. Furthermore, we discuss the non-trivial role of the exchange anisotropy within the chain.
  04/2011;