On-chip quantum sensing of Kondo spins in a high-mobility quasi-one-dimensional nanoconstriction

Abstract

The precise nature of Kondo spins has remained enigmatic when extended to multiple spin impurities or, more intriguingly, when the localized spin itself may already be the consequence of many-body interactions in a presumably-delocalized open nanoconstriction, such as a quantum point contact (QPC). It is experimentally challenging to distinguish the Kondo state from other coexisting many-body spin states in such a strongly correlated system. Here we lithographically define an all-on-chip electronic resonator (ER) and a QPC in a high-mobility GaAs/AlGaAs heterostructure transistor. Local Kondo screening of the QPC spin and nonlocal spin singlet across the ER-QPC integration are controllable in response to ER occupancy parity. We also show that the 0.7 anomaly, another strongly-correlated state in QPCs, not only has a different physical origin but furthermore counteracts the Kondo spin singlet. These results demonstrate a noninvasive quantum method for sensing spontaneous magnetic impurities within an open nanoconstriction.

18 pages, 4 figures

References in corpus (18)

• Observation of the two-channel Kondo effect
• All-electric all-semiconductor spin field effect transistors
• Quantum phase transition in a single-molecule quantum dot
• Magnetic impurity formation in quantum point contacts
• Nonequilibrium Singlet-Triplet Kondo Effect in Carbon Nanotubes
• Fermi surface in the absence of a Fermi liquid in the Kondo insulator SmB${}_6$
• Interplay between Kondo effect and Ruderman-Kittel-Kasuya-Yosida interaction
• Transition from a one-dimensional to a quasi-one-dimensional state in interacting quantum wires
• Effects of short-range interactions on transport through quantum point contacts: A numerical approach
• Spin coupling in zigzag Wigner crystals
• Controlled spatial separation of spins and coherent dynamics in spin-orbit-coupled nanostructures
• Ferromagnetic Spin Coupling as the Origin of 0.7 Anomaly in Quantum Point Contacts
• Modulated Kondo screening along magnetic mirror twin boundaries in monolayer MoS2 on graphene
• Detector Backaction on the Self-Consistent Bound State in Quantum Point Contacts
• Tuning the Fano Resonance with an Intruder Continuum
• Observation of Kondo condensation in a degenerately doped silicon metal
• Kondo effect in electrostatically defined ZnO quantum dots
• Observation of Electronic Modes in Open Cavity Resonator