Optimal Entanglement Witness for Cooper Pair Splitters
arXiv:2110.04783 · doi:10.1103/PhysRevB.104.245425
Abstract
The generation of spin-entangled electrons is an important prerequisite for future solid-state quantum technologies. Cooper pairs in a superconductor can be split into separate electrons in a spin-singlet state, however, detecting their entanglement remains an open experimental challenge. Proposals to detect the entanglement by violating a Bell inequality typically require a large number of current cross-correlation measurements, and not all entangled states can be detected in this way. Here, we instead formulate an entanglement witness that can detect the spin-entanglement using only three cross-correlation measurements of the currents in the outputs of a Cooper pair splitter. We identify the optimal measurement settings for witnessing the entanglement, and we illustrate the use of our entanglement witness with a realistic model of a Cooper pair splitter for which we evaluate the cross-correlations of the output currents. Specifically, we find that the entanglement of the spins can be detected even with a moderate level of decoherence. Our work thereby paves the way for an experimental detection of the entanglement produced by Cooper pair splitters.
arXiv comment11 pages, 4 figures
References in corpus (47)
- Spins in few-electron quantum dots
- Shot Noise in Mesoscopic Conductors
- Quantum state engineering with Josephson-junction devices
- Entanglement detection
- The Quantum Jump Approach to Dissipative Dynamics in Quantum Optics
- Nonequilibrium fluctuations, fluctuation theorems, and counting statistics in quantum systems
- Coherent control of a single electron spin with electric fields
- Bell Inequalities and the Separability Criterion
- Andreev-Tunneling, Coulomb Blockade, and Resonant Transport of Non-Local Spin-Entangled Electrons
- Full Counting Statistics of Charge Transfer in Coulomb Blockade Systems
- Carbon Nanotubes as Cooper Pair Beam Splitters
- Detecting Genuine Multipartite Entanglement with Two Local Measurements
- Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
- Electronic Entanglement in the Vicinity of a Superconductor
- Detection of entanglement with few local measurements
- Two-particle Aharonov-Bohm effect and Entanglement in the electronic Hanbury Brown Twiss setup
- Experimental observation of bias-dependent non-local Andreev reflection
- Orbital entanglement and violation of Bell inequalities in mesoscopic conductors
- Bell inequalities and entanglement in solid state devices
- Near-unity Cooper pair splitting efficiency
- Production and detection of entangled electron-hole pairs in a degenerate electron gas
- Finite bias Cooper pair splitting
- Spin-Orbit Mediated Control of Spin Qubits
- Full counting statistics of nano-electromechanical systems
- Cooper Pair Splitting by means of Graphene Quantum Dots
- Nonlocal entanglement in hybrid superconducting and normal-metal three terminal devices
- Superconducting proximity effect in interacting double-dot systems
- Test of Bell's Inequality using the Spin Filter Effect in Ferromagnetic Semiconductor Micro-structures
- Magnetic field tuning and quantum interference in a Cooper pair splitter
- Strong coupling between an electron in a quantum dot circuit and a photon in a cavity
- Entanglement detection from conductance measurements in carbon nanotube Cooper pair splitters
- Quantum master equations for the superconductor--dot entangler
- Local electrical tuning of the nonlocal signals in a Cooper pair splitter
- Quantum state tomography with quantum shotnoise
- Entanglement witnessing and quantum cryptography with non-ideal ferromagnetic detectors
- Real-time observation of Cooper pair splitting showing strong non-local correlations
- A Ballistic Graphene Cooper Pair Splitter
- Adiabatic pumping in a double-dot Cooper-pair beam splitter
- Spin correlation and entanglement detection in Cooper pair splitters by current measurements using magnetic detectors
- Noise and full counting statistics of a Cooper pair splitter
- Minimal Entanglement Witness From Electrical Current Correlations
- Minimal tomography with entanglement witnesses
- Entanglement detection for electrons via witness operators
- Dynamic Cooper Pair Splitter
- Sub Decoherence Time Generation and Detection of Orbital Entanglement
- Full Counting Statistics of Generic Spin Entangler with Quantum Dot-Ferromagnet detectors
- Entanglement discrimination in multi-rail electron-hole currents