Magnetic alteration of entanglement in two-electron quantum dots

Abstract

Quantum entanglement is analyzed thoroughly in the case of the ground and lowest states of two-electron axially symmetric quantum dots under a perpendicular magnetic field. The individualparticle and the center-of-mass representations are used to study the entanglement variation at the transition from interacting to noninteracting particle regimes. The mechanism of symmetry breaking due to the interaction, that results in the states with symmetries related to the later representation only, being entangled even at the vanishing interaction, is discussed. The analytical expression for the entanglement measure based on the linear entropy is derived in the limit of noninteracting electrons. It reproduces remarkably well the numerical results for the lowest states with the magnetic quantum number M ≥ 2 in the interacting regime. It is found that the entanglement of the ground state is a discontinuous function of the field strength. A method to estimate the entanglement of the ground state, characterized by the quantum number M , with the aid of the magnetic field dependence of the addition energy is proposed.

Entanglement generation through particle detection in systems of identical fermions

“…There is widespread consensus that entanglement between identical fermions is associated with the quantum correlations exhibited on top of the Slater correlations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. This conception of entanglement in fermion systems is relevant, for instance, in atomic physics [18,19], in quantum chemistry [20], and in the study of quantum dots [21]. From this perspective, a single Slater determinant should be considered as a non-entangled state, thus leading to the notion of fermionic entanglement to account for the extra correlations beyond those due to the indistinguishability of the parties, and to the antisymmetric property of fermionic states.…”

Quantum computing with quantum-Hall edge state interferometry

“…5.1), on the other hand, an approximated analytical formula in stationary conditions can be obtained by using the empirical transmission coefficients of a realistic 2D QPC given in Eq. (35). The two-electron wave function and a transmitted component |φ T α(β) that are not identical, according to the findings of Ref.…”

Bipartite correlations in quantum resonance states

“…Entanglement is also used as an alternative measure of correlation in systems of interacting particles [3]. Considerable efforts have been made to understand quantum correlations in bound states of model systems such as the Moshinsky atom [4][5][6][7][8], quantum dot systems [9][10][11][12][13] or ultra-cold boson systems [14][15][16][17][18]. Moreover, in recent years, the helium atom and helium-like ions have been extensively studied in this context [19][20][21][22][23][24][25][26][27][28][29].…”