An elongated quantum dot as a distributed charge sensor

Abstract

Increasing the separation between semiconductor quantum dots offers scaling advantages by fa- cilitating gate routing and the integration of sensors and charge reservoirs. Elongated quantum dots have been utilized for this purpose in GaAs heterostructures to extend the range of spin-spin interactions. Here, we study a metal-oxide-semiconductor (MOS) device where two quantum dot arrays are separated by an elongated quantum dot (340 nm long, 50 nm wide). We monitor charge transitions of the elongated quantum dot by measuring radiofrequency single-electron currents to a reservoir to which we connect a lumped-element resonator. We operate the dot as a single electron box to achieve charge sensing of remote quantum dots in each array, separated by a distance of 510 nm. Simultaneous charge detection on both ends of the elongated dot demonstrates that the charge is well distributed across its nominal length, supported by the simulated quantum-mechanical electron density. Our results illustrate how single-electron boxes can be realised with versatile foot- prints that may enable novel and compact quantum processor layouts, offering distributed charge sensing in addition to the possibility of mediated coupling.

14 pages, 9 figures

References in corpus (12)

• An addressable quantum dot qubit with fault-tolerant control fidelity
• Universal control of a six-qubit quantum processor in silicon
• Two-qubit silicon quantum processor with operation fidelity exceeding 99%
• A high-sensitivity gate-based charge sensor in silicon
• Quantum error correction with silicon spin qubits
• Probing quantum devices with radio-frequency reflectometry
• A shuttling-based two-qubit logic gate for linking distant silicon quantum processors
• Spin filling of valley-orbit states in a silicon quantum dot
• Negative spin exchange in a multielectron quantum dot
• Nonlinear response and crosstalk of electrically driven silicon spin qubits
• Charge State Hysteresis in Semiconductor Quantum Dots
• Jellybean quantum dots in silicon for qubit coupling and on-chip quantum chemistry

Cited by in corpus (2)

• Electronic Wigner-Molecule Polymeric Chains in Elongated Silicon Quantum Dots and Finite-Length Quantum Wires
• A 2x2 quantum dot array in silicon with fully tuneable pairwise interdot coupling