Abstract
We study a device for entangling electrons as co-tunneling occurs through a quantum dot where on-site electron-electron interactions U are in place. The main advantage of this device is that single-particle processes are forbidden by energy conservation as proposed by Oliver et al. (Phys. Rev. Lett., 88 (2002) 7901). Within this model we calculated the two-electron transition amplitude, in terms of the T-matrix, to all orders in the coupling to the dot, and consider a finite lead bandwidth. The model filters singlet entangled pairs with the sole requirement of Pauli principle. Feynman paths involving consecutive and doubly occupied dot interfere destructively and produce a transition amplitude minimum at a critical value of the onsite repulsion U. Singlet filtering is demonstrated as a function of a gate voltage applied to the dot with a special resonance condition when the dot levels are symmetrically placed about the input lead energy.
Original language | English (US) |
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Pages (from-to) | 624-630 |
Number of pages | 7 |
Journal | EPL |
Volume | 66 |
Issue number | 5 |
DOIs | |
State | Published - Mar 1 2004 |
Externally published | Yes |
ASJC Scopus subject areas
- Physics and Astronomy(all)