Quantum Information Processing with Hybrid Superconducting Circuits – QIPHSC
Quantum Information Processing with Hybrid Superconducting Circuits
Quantum Information Processing with Hybrid Superconducting Circuits
Context and objectives
Traditional superconducting qubits are based on tunnel Josephson junctions and rely on macroscopic bosonic degrees of freedom. Electronic qubits are based on quantum dots and rely on microscopic fermionic degrees of freedom. The QIPHSC project propose to engineer a hybrid quantum object that shares both features. The strategy consists in isolating a unique fermionic degree of freedom from the superconducting condensate in order to form what one could call a «Superconducting Fermionic Qubit«. To achieve this ambitious goal, I propose to perform experiments using hybrid Josephson junctions, in which superconductors are connected through low-dimensional quantum conductors. In addition to its basic research goal, the QIPHSC project, through the technical means implemented, will participate in the development of the QCMX Lab, a newly created experimental research team at Ecole Polytechnique.
On the material side, our main strategy consists in using carbon nanotubes as low-dimensional quantum conductors. To do so, we develop in the QCMX Lab an in-situ source of carbon nanotube. This platform enables the nanofabrication, optical characterization and circuit integration of ultra-clean carbon nanotubes. On the measurement side, we couple the hybrid Josephson junction to a superconducting resonator and perform radio-frequency measurements, using the newly acquired microwave instruments and components with the ANR funding. Experiments are performed together with the post-doctoral associate hired with the QIPHSC project.
The PI participated in an experiment directly related to the architectures proposed in the QIPHSC project. This experiment was performed at MIT and demonstrates the coherent control of a graphene-based superconducting qubit. The carrier participated in the analysis and interpretation of the experimental results, as well as in the writing of an article that was published in the journal Nature Nanotechnology.
Together with the postdoctoral associate recruited in October 2020 on the QIPHSC project, we are working on our first experiments. We first seek to implement an on-chip spectrometer to perform photonic spectroscopy of Andreev's states in a carbon nanotube. After an initial design phase, we are in the process of nano-fabricating in clean room the first samples (chemistry, lithography, evaporation).
[1] J. I-J. Wang, et al., Nature Nanotechnology 14, 120-125 (2019)
Traditional superconducting qubits are based on tunnel Josephson junctions and rely on macroscopic degrees of freedom, namely the superconducting phase difference and the charge difference across the junction. They are therefore intrinsically bosonic by nature. Electronic spin qubits are based on electrons confined in quantum dots and rely on microscopic fermionic degrees of freedom. Here, I propose to engineer a novel elementary quantum object that shares both features. The strategy consists in isolating a unique fermionic degree of freedom from the superconducting condensate in order to form what one could call a "Superconducting Spin Qubit". To achieve this ambitious goal, I propose to perform circuit quantum electrodynamics experiments using hybrid Josephson junctions, in which superconductors are connected through low-dimensional quantum conductors such as carbon nanotubes or semiconducting nanowires. This work will pave the way for the detection of Majorana fermions, elusive quasiparticles that possess a non-abelian quantum statistic.
Beyond the Andreev and Majorana physics on which this project focuses, these hybrid c-QED architectures, which combine quantum conductors and superconducting resonators, provide innovative platforms for studying interesting quantum properties of electronic matter and microwave light. They have huge potential in terms of complexity and control and are promising for quantum information processing and quantum simulation perspectives.
Project coordination
Landry Bretheau (Laboratoire des solides irradiés)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Partnership
LSI Laboratoire des solides irradiés
Help of the ANR 320,760 euros
Beginning and duration of the scientific project:
January 2019
- 48 Months
