scholarly journals Entanglement-symmetry control in a quantum-dot Cooper-pair splitter

2017 ◽  
Vol 254 (3) ◽  
pp. 1600603 ◽  
Author(s):  
Robert Hussein ◽  
Alessandro Braggio ◽  
Michele Governale
Keyword(s):  
Quantum Dot ◽  
Cooper Pair

scholarly journals Cooper pair splitting in parallel quantum dot Josephson junctions

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
R. S. Deacon ◽  
A. Oiwa ◽  
J. Sailer ◽  
S. Baba ◽  
Y. Kanai ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Cooper Pair ◽  
Josephson Current ◽  
Cooper Pairs ◽  
Electron Pairs ◽  
On Demand ◽  
Non Local ◽  
Local Transport ◽  
Current Flows ◽  
A Current

Abstract Devices to generate on-demand non-local spin entangled electron pairs have potential application as solid-state analogues of the entangled photon sources used in quantum optics. Recently, Andreev entanglers that use two quantum dots as filters to adiabatically split and separate the quasi-particles of Cooper pairs have shown efficient splitting through measurements of the transport charge but the spin entanglement has not been directly confirmed. Here we report measurements on parallel quantum dot Josephson junction devices allowing a Josephson current to flow due to the adiabatic splitting and recombination of the Cooper pair between the dots. The evidence for this non-local transport is confirmed through study of the non-dissipative supercurrent while tuning independently the dots with local electrical gates. As the Josephson current arises only from processes that maintain the coherence, we can confirm that a current flows from the spatially separated entangled pair.

Out-of-phase Andreev transports in a double-quantum-dot Cooper-pair splitter

2016 ◽  
Vol 119 (21) ◽  
pp. 214305 ◽  
Author(s):  
Wei-Jiang Gong ◽  
Xiao-Qi Wang ◽  
Yu-Lian Zhu ◽  
Zhen Gao ◽  
Hai-Na Wu
Keyword(s):  
Quantum Dot ◽  
Cooper Pair ◽  
Double Quantum ◽  
Double Quantum Dot

scholarly journals Erratum: Cooper pair splitting in parallel quantum dot Josephson junctions

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
R. S. Deacon ◽  
A. Oiwa ◽  
J. Sailer ◽  
S. Baba ◽  
Y. Kanai ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Josephson Junctions ◽  
Cooper Pair ◽  
Cooper Pair Splitting

scholarly journals Transport signatures of an Andreev molecule in a quantum dot–superconductor–quantum dot setup

2019 ◽  
Vol 10 ◽  
pp. 363-378 ◽  
Author(s):  
Zoltán Scherübl ◽  
András Pályi ◽  
Szabolcs Csonka
Keyword(s):  
Quantum Dots ◽  
Quantum Information ◽  
Quantum Dot ◽  
Cooper Pair ◽  
Differential Conductance ◽  
Zero Bias ◽  
Local Mechanism ◽  
Special Cases ◽  
Non Local ◽  
Hybrid Devices

Hybrid devices combining quantum dots with superconductors are important building blocks of conventional and topological quantum-information experiments. A requirement for the success of such experiments is to understand the various tunneling-induced non-local interaction mechanisms that are present in the devices, namely crossed Andreev reflection, elastic co-tunneling, and direct interdot tunneling. Here, we provide a theoretical study of a simple device that consists of two quantum dots and a superconductor tunnel-coupled to the dots, often called a Cooper-pair splitter. We study the three special cases where one of the three non-local mechanisms dominates, and calculate measurable ground-state properties, as well as the zero-bias and finite-bias differential conductance characterizing electron transport through this device. We describe how each non-local mechanism controls the measurable quantities, and thereby find experimental fingerprints that allow one to identify and quantify the dominant non-local mechanism using experimental data. Finally, we study the triplet blockade effect and the associated negative differential conductance in the Cooper-pair splitter, and show that they can arise regardless of the nature of the dominant non-local coupling mechanism. Our results should facilitate the characterization of hybrid devices, and their optimization for various quantum-information-related experiments and applications.

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