Non-universal transmission phase behaviour of a large quantum dot

Abstract

The electron wave function experiences a phase modification at coherent transmission through a quantum dot. This transmission phase undergoes a characteristic shift of $\pi$ when scanning through a Coulomb-blockade resonance. Between successive resonances either a transmission phase lapse of $\pi$ or a phase plateau is theoretically expected to occur depending on the parity of the corresponding quantum dot states. Despite considerable experimental effort, this transmission phase behaviour has remained elusive for a large quantum dot. Here we report on transmission phase measurements across such a large quantum dot hosting hundreds of electrons. Using an original electron two-path interferometer to scan the transmission phase along fourteen successive resonances, we observe both phase lapses and plateaus. Additionally, we demonstrate that quantum dot deformation alters the sequence of transmission phase lapses and plateaus via parity modifications of the involved quantum dot states. Our findings set a milestone towards a comprehensive understanding of the transmission phase of quantum dots.

Main paper: 18 pages, 5 figures, Supplementary materials: 8 pages, 4 figures

References in corpus (6)

• Finite bias visibility of the electronic Mach-Zehnder interferometer
• Electrical control of a solid-state flying qubit
• Decoherence and single electron charging in an electronic Mach-Zehnder interferometer
• Magnetic field dependent transmission phase of a double dot system in a quantum ring
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Cited by in corpus (6)

• Transmission phase read-out of a large quantum dot in a nanowire interferometer
• Entanglement generation via power-of-SWAP operations between dynamic electron-spin qubits
• Robust conductance zeroes in graphene quantum dots and other bipartite systems
• In-flight detection of few electrons using a singlet-triplet spin qubit
• Transfer-matrix summation of path integrals for transport through nanostructures
• Correlation between peak-height modulation and phase-lapses in transport through quantum dots