A5036005856- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Cold Atom Physics and Bose-Einstein Condensates
Universidad Autónoma de Madrid
2022-2024
Andreev bound states are fermionic localized in weak links between superconductors, which can be occupied with spinful quasiparticles. Recently, experiments embedding a nanowire Josephson junction into superconducting circuit have enabled coherent manipulation of single spin. However, these remained limited to small magnetic fields. Here, the authors measure microwave spectra fields up $\ensuremath{\sim}$ 250 mT and identify singlet, doublet, triplet interacting spins.
We performed microwave spectroscopy of an InAs nanowire between superconducting contacts implementing a finite-length, multichannel Josephson weak link. Certain features in the spectra, such as splitting by spin-orbit interactions transition lines among Andreev states, have been already understood terms noninteracting models. However, we identify here additional transitions, which evidence presence Coulomb interactions. By combining experimental measurements and model calculations, reach...
We probed a gate-tunable InAs nanowire Josephson weak link by coupling it to microwave resonator. Tracking the resonator frequency shift when is close pinch-off, we observe that ground state of latter alternates between singlet and doublet varying either gate voltage or superconducting phase difference across it. The corresponding absorption spectra display lines approach zero energy singlet-doublet boundaries, suggesting parity flipping transitions, which are in principle forbidden...
We explore superconducting quantum circuits where several leads are simultaneously connected beyond the tunneling regime, such that fermionic structure of Andreev bound states in resulting multiterminal Josephson junction influences full circuit. Using a simple model single-channel contacts and single level middle region, we discuss different circuit configurations islands with finite capacitance and/or form loops inductance. find situations practical interest can be used to define...
Andreev bound states are fermionic localized in weak links between superconductors which can be occupied with spinful quasiparticles. Microwave experiments using superconducting circuits InAs/Al nanowire Josephson junctions have recently enabled probing and coherent manipulation of but remained limited to zero or small fields. Here we use a flux-tunable circuit external magnetic fields up 1T perform spectroscopy spin-polarized ~250 mT, beyond the spectrum becomes gapless. We identify singlet...
We explore superconducting quantum circuits where several leads are simultaneously connected beyond the tunneling regime, such that fermionic structure of Andreev bound states in resulting multiterminal Josephson junction influences full circuit. Using a simple model single channel contacts and level middle region, we discuss different circuit configurations islands with finite capacitance and/or form loops inductance. find situations practical interest can be used to define noise protected...