We study entanglement generated between a qubit and a super-ohmic bosonic bath due to their joint evolution which leads to pure dephasing of the qubit. We tune the parameters of the interaction, so that the decoherence is quantitatively independent of the number of bosonic modes taken into account (and corresponds to realistic decoherence seen in small excitonic quantum dots coupled to an environment of phonons) and investigate, how the entanglement generated depends on the size of the environment. A second parameter of interest is the mixedness of the initial state of the environment which is controlled by temperature. We show analytically that for a pure initial state of the environment (zero temperature here), entanglement does not depend on environment size. At finite temperatures (mixed initial state of the environment), the generated entanglement decreases with the increase of environment size. This effect is stronger for larger temperatures, when the environment is initially more mixed, but in the limit of an infinitely large environment, no entanglement is created at any finite temperature.We study entanglement generated between a qubit and a super-ohmic bosonic bath due to their joint evolution which leads to pure dephasing of the qubit. We tune the parameters of the interaction, so that the decoherence is quantitatively independent of the number of bosonic modes taken into account (and corresponds to realistic decoherence seen in small excitonic quantum dots coupled to an environment of phonons) and investigate, how the entanglement generated depends on the size of the environment. A second parameter of interest is the mixedness of the initial state of the environment which is controlled by temperature. We show analytically that for a pure initial state of the environment (zero temperature here), entanglement does not depend on environment size. At finite temperatures (mixed initial state of the environment), the generated entanglement decreases with the increase of environment size. This effect is stronger for larger temperatures, when the environment is initially more mixed, but in the limit of an infinitely large environment, no entanglement is created at any finite temperature.

Apr 26, 20170 citations

Entanglement dynamics of two qubits induced by a reservoir of coupled bosons

Zhongjie Wang, Qijia Tai

OptikMar 11, 20160 citations

Mobility and diffusion of a particle coupled to a Luttinger liquid

A. H. Castro Neto, A. O. Caldeira

We study the mobility of a particle coupled to a one-dimensional interacting fermionic system, namely, a Luttinger liquid. We bosonize the Luttinger liquid and find the effective interaction between the particle and the bosonic system. We show that the dynamics of this system is completely equivalent to the acoustic polaron problem where the interaction has purely electronic origin. This problem has a zero-mode excitation, or soliton, in the strong-coupling limit, which corresponds to the the formation of a polarization cloud due to the fermion-fermion interaction around the particle. We find that, due to the scattering of the residual bosonic modes, the soliton has a finite mobility and diffusion coefficient at finite temperatures that depend on the fermion-fermion interaction. We show that at low temperatures the mobility and the diffusion coefficient are proportional to ${\mathit{T}}^{\mathrm{\ensuremath{-}}4}$ and ${\mathit{T}}^{5}$ , respectively, and at high temperatures the mobility vanishes as ${\mathit{T}}^{\mathrm{\ensuremath{-}}1}$ while the diffusion increases as T.We study the mobility of a particle coupled to a one-dimensional interacting fermionic system, namely, a Luttinger liquid. We bosonize the Luttinger liquid and find the effective interaction between the particle and the bosonic system. We show that the dynamics of this system is completely equivalent to the acoustic polaron problem where the interaction has purely electronic origin. This problem has a zero-mode excitation, or soliton, in the strong-coupling limit, which corresponds to the the formation of a polarization cloud due to the fermion-fermion interaction around the particle. We find that, due to the scattering of the residual bosonic modes, the soliton has a finite mobility and diffusion coefficient at finite temperatures that depend on the fermion-fermion interaction. We show that at low temperatures the mobility and the diffusion coefficient are proportional to ${\mathit{T}}^{\mathrm{\ensuremath{-}}4}$ and ${\mathit{T}}^{5}$, respectively, and at high temperatures the mobility vanishes as ${\mathit{T}}^{\mathrm{\ensuremath{-}}1}$ while the diffusion increases as T.

arXiv:cond-mat/9403043Physical review. B, Condensed matterAug 15, 199421 citations

Entanglement dynamics of two-qubit pure state

Jun Zhang

Quantum Information ProcessingMay 3, 20124 citations

Exact Liouvillian spectral reconstruction for a finite-temperature bosonic mode

Leonardi Hernández-Sánchez, I. Ramos-Prieto, Francisco Soto‐Eguibar +1 more

We present an exact Liouvillian spectral reconstruction for a finite-temperature bosonic mode, including eigenvalues, physical eigenoperators, and expansion coefficients for arbitrary initial conditions. The eigenvalues are independent of the thermal occupation, whereas the physical eigenoperators retain the reservoir-temperature dependence, with the thermal stationary state corresponding to the zero Liouvillian mode. Photon-number statistics and two-time correlations connect the spectral structure with relaxation, fluctuations, and temporal coherence by revealing the Liouvillian sectors selected by different observables. The zero-temperature dynamics are recovered in the limit ̅ ̅ ̅ ̅ ̅ 𝑛 → 0 .We present an exact Liouvillian spectral reconstruction for a finite-temperature bosonic mode, including eigenvalues, physical eigenoperators, and expansion coefficients for arbitrary initial conditions. The eigenvalues are independent of the thermal occupation, whereas the physical eigenoperators retain the reservoir-temperature dependence, with the thermal stationary state corresponding to the zero Liouvillian mode. Photon-number statistics and two-time correlations connect the spectral structure with relaxation, fluctuations, and temporal coherence by revealing the Liouvillian sectors selected by different observables. The zero-temperature dynamics are recovered in the limit ̅ ̅ ̅ ̅ ̅ 𝑛 → 0 .

Physics Letters AOct 21, 20260 citations

{\mathit{T}}^{5}

, respectively, and at high temperatures the mobility vanishes as ${\mathit{T}}^{\mathrm{\ensuremath{-}}1}$ while the diffusion increases as T.