Jiang Cao^1*, Guido Gandus^1*, Tarun Agarwal², Mathieu Luisier¹, Youseung Lee^1*

1 Integrated Systems Laboratory, ETH Zürich, 8092 Zurich, Switzerland

2 Department of Electrical Engineering, IIT Gandhinagar, Palaj, Gujarat 382355, India

* Corresponding authors emails: jiacao@ethz.ch, ggandus@student.ethz.ch, youslee@ethz.ch

DOI10.24435/materialscloud:nh-nk [version v1]

Publication date: Nov 15, 2022

How to cite this record

Jiang Cao, Guido Gandus, Tarun Agarwal, Mathieu Luisier, Youseung Lee, Dynamics of van der Waals charge qubit in two-dimensional bilayer materials: Ab initio quantum transport and qubit measurement, Materials Cloud Archive 2022.148 (2022), doi: 10.24435/materialscloud:nh-nk.

Description

A van der Waals (vdW) charge qubit, electrostatically confined within two-dimensional (2D) vdW materials, is proposed as a building block of future quantum computers. Its characteristics are systematically evaluated with respect to its two-level anticrossing energy difference (Δ). Bilayer graphene (Δ≈ 0) and a vdW heterostructure (Δ≫ 0) are used as representative examples. Their tunable electronic properties with an external electric field define the state of the charge qubit. By combining density functional theory and quantum transport calculations, we highlight the optimal qubit operation conditions based on charge stability and energy-level diagrams. Moreover, a single-electron transistor design based on trilayer vdW heterostructures capacitively coupled to the charge qubit is introduced as a measurement setup with low decoherence and improved measurement properties. It is found that a Δ greater than 20 meV results in a rapid mixing of the qubit states, which leads to a lower measurement quantity, i.e., contrast and conductance. With properly optimized designs, qubit architectures relying on 2D vdW structures could be integrated into an all-electronic quantum computing platform.

Materials Cloud sections using this data

Files

File name	Size	Description
for_marvel.tar.gz MD5md5:18cb2df5ec8fe80b5c8800dd58555428	3.6 MiB	Quantum Espresso, Wannier90 input files and quantum transport (OMEN) simulation files of van der Waals charge qubit and QuTiP simulation files of combined system of the single-electron transistor and qubit.

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External references

Keywords

Bilayer graphene Quantum transport van der Waals qubit Nonequilibrium Green's function Single-electron transistors MARVEL Marie Curie Fellowship