Descrizione del progetto
Un percorso per testare l’entanglement quantistico su vasta scala grazie ai nanotubi in carbonio
I nanotubi in carbonio sono particolarmente idonei a ospitare i qubit di spin, grazie alle loro proprietà elettroniche uniche e alla capacità di cui sono dotati per confinare gli elettroni nei punti quantici. Finanziato dal Consiglio europeo della ricerca, il progetto CNT-QUBIT mira a sviluppare un sistema scalabile, interamente elettrico, in grado di stabilire l’entanglement quantistico, che costituisce un requisito fondamentale per l’informatica quantistica, attraverso le misurazioni. CNT-QUBIT utilizzerà le interazioni spin-orbita per le rotazioni di spin e le interazioni iperfini per la memorizzazione di informazioni quantistiche. Le attività svolte nell’ambito del progetto prevedono l’accoppiamento di due qubit di spin spazialmente separati tra loro con un singolo risonatore elettrico, con conseguente entanglement qualora risultino indistinguibili dalle misurazioni. L’informazione quantistica contenuta nei qubit di spin degli elettroni entangled verrà trasferita agli spin nucleari del carbonio-13, che dovrebbero fungere da memoria quantistica con lunghi tempi di coerenza.
Obiettivo
The aim of this proposal is to use spin qubits defined in carbon nanotube quantum dots to demonstrate measurement-based entanglement in an all-electrical and scalable solid-state architecture. The project makes use of spin-orbit interaction to drive spin rotations in the carbon nanotube host system and hyperfine interaction to store quantum information in the nuclear spin states. The proposal builds on techniques developed by the principal investigator for fast and non-invasive read-out of the electron spin qubits using radio-frequency reflectometry and spin-to-charge conversion.
Any quantum computer requires entanglement. One route to achieve entanglement between electron spin qubits in quantum dots is to use the direct interaction of neighbouring qubits due to their electron wavefunction overlap. This approach, however, becomes rapidly impractical for any large scale quantum processor, as distant qubits can only be entangled through the use of qubits in between. Here I propose an alternative strategy which makes use of an intriguing quantum mechanical effect by which two spatially separated spin qubits coupled to a single electrical resonator become entangled if a measurement cannot tell them apart.
The quantum information encoded in the entangled electron spin qubits will be transferred to carbon-13 nuclear spins which are used as a quantum memory with coherence times that exceed seconds. Entanglement with further qubits then proceeds again via projective measurements of the electron spin qubits without risk of losing the existing entanglement. When entanglement of the electron spin qubits is heralded – which might take several attempts – the quantum information is transferred again to the nuclear spin states. This allows for the coupling of large numbers of physically separated qubits, building up so-called graph or cluster states in an all-electrical and scalable solid-state architecture.
Campo scientifico
- engineering and technologyelectrical engineering, electronic engineering, information engineeringinformation engineeringtelecommunicationsradio technologyradio frequency
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringcomputer hardwarequantum computers
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringsensors
Programma(i)
Argomento(i)
Meccanismo di finanziamento
ERC-COG - Consolidator GrantIstituzione ospitante
WC1E 6BT London
Regno Unito