Related Experiment Video
Updated: Jan 30, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
10.4K
Germanium Quantum-Well Josephson Field-Effect Transistors and Interferometers.
Florian Vigneau1, Raisei Mizokuchi1, Dante Colao Zanuz1
1Université Grenoble Alpes, CEA, INAC-Pheliqs , 38000 Grenoble , France.
Nano Letters
|January 12, 2019
Summary
Researchers created novel hybrid superconductor-semiconductor devices using germanium channels and aluminum leads. These Josephson field-effect transistors demonstrate gate-controlled supercurrents, advancing quantum computing applications.
Area of Science:
- Condensed Matter Physics
- Quantum Computing
Background:
- Hybrid superconductor-semiconductor structures are crucial for quantum computing.
- Topological superconducting systems and tunable superconducting qubits are key applications.
Purpose of the Study:
- To realize prototypical hybrid devices using SiGe/Ge/SiGe heterostructures and aluminum leads.
- To investigate gate-controlled supercurrent transport in germanium channels.
Main Methods:
- Fabrication of hybrid devices including Josephson field-effect transistors (JoFETs) and superconducting quantum interference devices (SQUIDs).
- Utilizing SiGe/Ge/SiGe quantum-well heterostructures with two-dimensional holes.
- Employing tunnel spectroscopy to estimate the induced superconducting gap.
- Transmission electron microscopy for interface analysis.
Main Results:
- Observed gate-controlled supercurrent transport in germanium channels up to one micrometer.
- Estimated the induced superconducting gap.
- Transmission electron microscopy confirmed germanium diffusion into aluminum contacts, with no aluminum detected in the germanium channel.
Conclusions:
- Demonstrated the feasibility of hybrid superconductor-semiconductor devices for quantum applications.
- Highlighted the potential of germanium channels for realizing advanced quantum devices.
- Interface properties are critical for device performance.
Related Concept Videos
01:29Field Effect Transistor
1.2K
Field-effect transistors (FETs) are integral to electronic circuits and distinguished by their three-terminal setup: the gate, drain, and source. These transistors operate as unipolar devices, which utilize either electrons or holes as charge carriers, in contrast to bipolar transistors, which use both types of carriers. The primary function of the FET is to modulate the flow of these carriers from the source to the drain through a channel. The voltage difference between the gate and source...
1.2K
02:43Quantum Numbers
50.0K
It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy level to another but not transition smoothly or stay between these levels.
50.0K
02:45The Quantum-Mechanical Model of an Atom
57.3K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
57.3K
01:22Bipolar Junction Transistor
1.5K
Bipolar Junction Transistors (BJTs) are essential elements in electronic circuits, playing a crucial role in the functionality of amplifiers, memories, and microprocessors. These transistors can be designed as NPN or PNP based on their doping patterns. They consist of three layers: the emitter, base, and collector. The configuration of these layers and their respective doping levels—with N-type or P-type impurities—define the transistor's type and its operational...
1.5K
01:16Electric Field
12.8K
Consider two point charges, each exerting Coulomb force on the other. It is possible to describe the Coulomb interaction via an intermediate step by defining a new physical quantity called the electric field.
In the new picture, imagine that the first charge sets up an electric field independent of all other charges in the universe. When another charge comes in its vicinity, the second charge experiences an electric force depending on the electric field at that point. The source charge does not...
In the new picture, imagine that the first charge sets up an electric field independent of all other charges in the universe. When another charge comes in its vicinity, the second charge experiences an electric force depending on the electric field at that point. The source charge does not...
12.8K
01:27Magnetic Fields
7.3K
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
7.3K