Double quantum dot Cooper-pair splitter at finite couplings

Hussein, Robert; Jaurigue, Lina; Governale, Michele; Braggio, Alessandro

doi:10.1103/physrevb.94.235134

Cited by 24 publications

(39 citation statements)

References 95 publications

(101 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have already shown in Ref. that entanglement in the system may still be generated even without nonlocal coupling

Γ_{S} = 0

. However, in the following we do not specifically consider this case, since to obtain the maximal nonlocal entanglement it is advantageous to keep the nonlocal coupling finite.…”

Section: Resonant Current Peaks and Entanglementmentioning

confidence: 99%

“…Therefore, we can restrict ourselves to the occupation probabilities

P_{a}

for the eigenstate

|a〉

H_{S}

, which obey the master equation

{\dot{P}}_{a} = \sum_{a^{'}} false(w_{a \leftarrow a^{'}} P_{a^{'}} - w_{a^{'} \leftarrow a} P_{a} false)

in lowest order in the tunneling rates to the normal leads . The tunneling rates

w_{a \leftarrow a^{'}}

for the transition from the state

|a′ 〉

to the state

|a〉

can be obtained by Fermi's golden rule

\begin{matrix} right w_{a \leftarrow a^{'}} (boldχ) & center = & left Γ_{N} \sum_{α σ} e^{i χ_{α}} false[1 - f_{α} false(E_{a^{'}} - E_{a} false) false] | {〈 a | d_{ασ} | a′ 〉}^{2} | \\ right & center & left + Γ_{N} \sum_{α σ} e^{- i χ_{α}} f_{α} (E_{a} - E_{a^{'}}) | {〈 a | d_{α σ}^{†} | a' 〉}^{2} |, \end{matrix}

with

f_{α} false(ϵ false) = {1 + exp false[false(ϵ - μ_{α} false) / k_{B} T false]}^{- 1}

being the Fermi function of the normal lead

α

…”

Section: Model and Formalismmentioning

confidence: 99%

“…The interested reader can find a more detailed discussion of the effect of structural asymmetry, including different Coulomb energies for the two dots, in the Appendix B of Ref. . We consider symmetric bias voltages

μ \equiv μ_{L} = μ_{R}

and level positions

ϵ \equiv ϵ_{L} = ϵ_{R}

which is the optimal point to develop spatial entanglement in the system.…”

Section: Resonant Current Peaks and Entanglementmentioning

confidence: 99%

“…In Ref. , we discussed only the two cases

φ = 0

and

φ = π / 2

for the SO angle, which are representative for the behavior of the system with interdot tunneling when the SO effect is absent or when it is maximal, respectively. These two cases crucially differ in the symmetry of the entanglement developed in the DQD at the nonlocal resonance.…”

Section: Resonant Current Peaks and Entanglementmentioning

confidence: 99%

See 3 more Smart Citations

Entanglement‐symmetry control in a quantum‐dot Cooper‐pair splitter

Hussein

Braggio²,

Governale

2017

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

The control of nonlocal entanglement in solid state systems is a crucial ingredient of quantum technologies. We investigate a Cooper-pair splitter based on a double quantum dot realised in a semiconducting nanowire. In the presence of interdot tunnelling the system provides a simple mechanism to develop spatial entanglement even in absence of nonlocal coupling with the superconducting lead. We discuss the possibility to control the symmetry (singlet or triplet) of spatially separated, entangled electron pairs taking advantage of the spin-orbit coupling of the nanowire. We also demonstrate that the spin-orbit coupling does not impact over the entanglement purity of the nonlocal state generated in the double quantum dot system.Comment: 7 pages, 3 figure

show abstract

“…We have already shown in Ref. that entanglement in the system may still be generated even without nonlocal coupling

Γ_{S} = 0

. However, in the following we do not specifically consider this case, since to obtain the maximal nonlocal entanglement it is advantageous to keep the nonlocal coupling finite.…”

Section: Resonant Current Peaks and Entanglementmentioning

confidence: 99%

“…Therefore, we can restrict ourselves to the occupation probabilities

P_{a}

for the eigenstate

|a〉

H_{S}

, which obey the master equation

{\dot{P}}_{a} = \sum_{a^{'}} false(w_{a \leftarrow a^{'}} P_{a^{'}} - w_{a^{'} \leftarrow a} P_{a} false)

in lowest order in the tunneling rates to the normal leads . The tunneling rates

w_{a \leftarrow a^{'}}

for the transition from the state

|a′ 〉

to the state

|a〉

can be obtained by Fermi's golden rule

\begin{matrix} right w_{a \leftarrow a^{'}} (boldχ) & center = & left Γ_{N} \sum_{α σ} e^{i χ_{α}} false[1 - f_{α} false(E_{a^{'}} - E_{a} false) false] | {〈 a | d_{ασ} | a′ 〉}^{2} | \\ right & center & left + Γ_{N} \sum_{α σ} e^{- i χ_{α}} f_{α} (E_{a} - E_{a^{'}}) | {〈 a | d_{α σ}^{†} | a' 〉}^{2} |, \end{matrix}

with

f_{α} false(ϵ false) = {1 + exp false[false(ϵ - μ_{α} false) / k_{B} T false]}^{- 1}

being the Fermi function of the normal lead

α

…”

Section: Model and Formalismmentioning

confidence: 99%

μ \equiv μ_{L} = μ_{R}

and level positions

ϵ \equiv ϵ_{L} = ϵ_{R}

which is the optimal point to develop spatial entanglement in the system.…”

Section: Resonant Current Peaks and Entanglementmentioning

confidence: 99%

“…In Ref. , we discussed only the two cases

φ = 0

and

φ = π / 2

Section: Resonant Current Peaks and Entanglementmentioning

confidence: 99%

See 2 more Smart Citations

Entanglement‐symmetry control in a quantum‐dot Cooper‐pair splitter

Hussein

Braggio²,

Governale

2017

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

show abstract

“…One of very promising applications of such hybrid systems is the possibility to realize a Cooper pair splitter (CPS) [19,20,21,22,23,24,25,26,27,28,29,30]. In Cooper pair splitting devices the electrons forming a Cooper pair tunnel from superconductor into two separate normal leads, while the tunability of quantum dots embedded in the arms of a CPS enables controlling of the splitting process [20,21,22].…”

Section: Introductionmentioning

confidence: 99%

Current cross-correlations in double quantum dot based Cooper pair splitters with ferromagnetic leads

Wrześniewski

Trocha

Weymann

2017

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Abstract. We investigate the current cross-correlations in a double quantum dot based Cooper pair splitter coupled to one superconducting and two ferromagnetic electrodes. The analysis is performed by assuming a weak coupling between the double dot and ferromagnetic leads, while the coupling to the superconductor is arbitrary. Employing the perturbative real-time diagrammatic technique, we study the Andreev transport properties of the device, focusing on the Andreev current cross-correlations, for various parameters of the model, both in the linear and nonlinear response regimes. Depending on parameters and transport regime, we find both positive and negative current cross-correlations. Enhancement of the former type of cross-correlations indicates transport regimes, in which the device works with high Cooper pair splitting efficiency, contrary to the latter type of correlations, which imply negative influence on the splitting. The processes and mechanisms leading to both types of current cross-correlations are thoroughly examined and discussed, giving a detailed insight into the Andreev transport properties of the considered device.PACS numbers: 73.21.La,74.45.+c,

show abstract

Stability Study and Decay Mechanism of Quantum Dot Light‐Emitting Diodes

2023

Colloidal Quantum Dot Light Emitting Diodes

View full text Add to dashboard Cite

Double quantum dot Cooper-pair splitter at finite couplings

Cited by 24 publications

References 95 publications

Entanglement‐symmetry control in a quantum‐dot Cooper‐pair splitter

Entanglement‐symmetry control in a quantum‐dot Cooper‐pair splitter

Current cross-correlations in double quantum dot based Cooper pair splitters with ferromagnetic leads

Stability Study and Decay Mechanism of Quantum Dot Light‐Emitting Diodes

Contact Info

Product

Resources

About