A Resonant-Tunneling Quantum-Dot Demultiplexer for Scalable Cryogenic Single-Electron Routing
Abstract
Scaling quantum electronic systems such as quantum-dot spin qubits and single-electron devices is increasingly limited by the wiring overhead between cryogenic devices and room-temperature control electronics. Multi-channel quantum-dot architectures that selectively route electrons using a few shared control lines, analogous to demultiplexers in classical networks, offer a promising solution. Here, we propose and theoretically investigate a gate-defined architecture of three parallel quantum dots sharing a common source reservoir and coupled to independent drain channels. Using an analytical electrostatic model and tight-binding quantum transport simulations, we show that the device can act as an on-chip single-electron demultiplexer based on resonant tunneling in the cryogenic regime. Closed-system eigenstate analysis reveals localized orbital states in each dot, and open-system transport calculations show resonant conductance peaks when these levels align with the incident electron energy, consistent with the closed-system eigenenergy evolution. By engineering the barrier-gate spacing and the relative plunger-gate dimensions, we obtain well-separated resonances with minimal overlap between channels. Bond-current density calculations show that transport is confined to the resonant channel with negligible leakage into neighboring outputs, yielding channel selectivity approaching unity for all resonant modes. The architecture is compatible with Si/SiGe and GaAs/AlGaAs platforms and can be extended to more channels, offering a route toward programmable quantum routing and resonant-tunneling-based quantum circuitry.
Related
- Quantum Well Resonant Tunneling Diode Probe of Correlated States in Twisted Bilayer MoS2
- A Cryogenic Hybrid Photonic/CMOS Controller Architecture for Scalable Superconducting Qubit Control
- Demonstration of a cryogenic, switchable electron source for low-temperature detector calibration
- Ultralow Mean Transverse Energy and High Quantum Efficiency Cryogenic Bialkali Photocathode for MHz-Repetition-Rate Electron Sources
- Cryogenic Enhancement of Electron Spin Polarization from a Strained GaAs/GaAsP Superlattice Photocathode
BibTeX
@misc{bharadwaj2026resonanttunneling,
title = {{A Resonant-Tunneling Quantum-Dot Demultiplexer for Scalable Cryogenic Single-Electron Routing}},
author = {Rajat Bharadwaj and Harshita Bose and Madhu Thalakulam},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.05194},
eprint = {2611.05194},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.05194},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - A Resonant-Tunneling Quantum-Dot Demultiplexer for Scalable Cryogenic Single-Electron Routing
AU - Rajat Bharadwaj
AU - Harshita Bose
AU - Madhu Thalakulam
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.05194
UR - https://arxiv.org/abs/2611.05194
AB - Scaling quantum electronic systems such as quantum-dot spin qubits and single-electron devices is increasingly limited by the wiring overhead between cryogenic devices and room-temperature control electronics. Multi-channel quantum-dot architectures that selectively route electrons using a few shared control lines, analogous to demultiplexers in classical networks, offer a promising solution. Here, we propose and theoretically investigate a gate-defined architecture of three parallel quantum dots sharing a common source reservoir and coupled to independent drain channels. Using an analytical electrostatic model and tight-binding quantum transport simulations, we show that the device can act as an on-chip single-electron demultiplexer based on resonant tunneling in the cryogenic regime. Closed-system eigenstate analysis reveals localized orbital states in each dot, and open-system transport calculations show resonant conductance peaks when these levels align with the incident electron energy, consistent with the closed-system eigenenergy evolution. By engineering the barrier-gate spacing and the relative plunger-gate dimensions, we obtain well-separated resonances with minimal overlap between channels. Bond-current density calculations show that transport is confined to the resonant channel with negligible leakage into neighboring outputs, yielding channel selectivity approaching unity for all resonant modes. The architecture is compatible with Si/SiGe and GaAs/AlGaAs platforms and can be extended to more channels, offering a route toward programmable quantum routing and resonant-tunneling-based quantum circuitry.
ER -