Quenched dynamics of entangled states in correlated quantum dots

Abstract

Time evolution of initially prepared entangled state in the system of coupled quantum dots has been analyzed by means of two different theoretical approaches: equations of motion for the all orders localized electron correlation functions, considering interference effects, and kinetic equations for the pseudo-particle occupation numbers with constraint on the possible physical states. Results obtained by means of different approaches were carefully analyzed and compared with each other. Revealed direct link between concurrence (degree of entanglement) and quantum dots pair correlation functions allowed us to follow the changes of entanglement during time evolution of the coupled quantum dots system. It was demonstrated that the degree of entanglement can be controllably tuned during the time evolution of quantum dots system.Comment: 8 pages, 3 figure

Quench dynamics of spin in quantum dots coupled to spin-polarized leads

“…However, an accurate description of dynamics in such systems poses a considerable challenge due to electronic correlations. Recently, there have been significant advances in this regard [25][26][27][28][29][30][31][32][33], especially by resorting to various renormalization group schemes [34][35][36][37][38][39][40][41][42][43][44].…”

Probing and driving of spin and charge states in double quantum dot under the quench

“…The proposed scheme allows to prepare controllable the maximally entangled pure triplet T 0 state and to drive the system from the T 0 state to the another entangled singlet S 0 state by applied bias and gate voltage changing. One could also follow time evolution of the degree of entanglement by analyzing the behavior of two-electron correlation functions 51 .…”

Spatial transfer of entangled states in the correlated quantum dots system

“…Among many systems where entangled states can be effectively formed and controlled, coupled quantum dots (QDs) recently got special attention since single-and two-electron states can be easily initialized, processed, and read out in such ultrasmall structures [12][13][14][15][16]. In double correlated QDs the entangled state can appear as an eigenstate with a particular number of electrons [17] or can be created by sending an electrical current through the nanoscale structure [18].…”

“…Entangled states of correlated QDs with particular symmetries could live long, and can be controlled with a high precision by applying bias [19,20] or external laser pulses [21,22]. The time evolution of entanglement in coupled QDs with Coulomb interaction was studied in [16,[23][24][25][26][27][28]. Two-electron spin qubits can be formed in coupled QDs by the singlet two-electron state and triplet state with zero spin projection on z-axis.…”