Related Experiment Video
Updated: Aug 26, 2025
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
9.7K
Selective control of conductance modes in multi-terminal Josephson junctions
Gino V Graziano1, Mohit Gupta1, Mihir Pendharkar2,3
1School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA.
Nature Communications
|October 8, 2022
Summary
Researchers created a platform for tunable topological phases in multi-terminal Josephson junctions. They achieved independent control over conductance modes, enabling access to the single-mode regime for experimental realization.
Area of Science:
- Condensed Matter Physics
- Quantum Information Science
- Materials Science
Background:
- Andreev bound state spectra in multi-terminal Josephson junctions mimic artificial band structures.
- These structures are theoretically predicted to host tunable topological phases.
- Experimental accessibility requires a limited number of conductance modes between terminals.
Purpose of the Study:
- To develop a method for controlling conductance modes in multi-terminal Josephson junctions.
- To achieve the single-mode regime necessary for observing topological phases.
- To establish a platform for realizing tunable Andreev bound state spectra.
Main Methods:
- Utilized a quantum point contact geometry in three-terminal Josephson devices.
- Demonstrated independent control of conductance modes between each terminal pair.
- Achieved coexistence of the single-mode regime with superconducting coupling.
Main Results:
- Independent control over individual conductance modes was successfully demonstrated.
- Access to the single-mode regime was achieved in a three-terminal setup.
- The developed system provides a viable platform for studying topological phases.
Conclusions:
- The quantum point contact geometry enables precise control over conductance modes.
- This work establishes a foundational platform for experimental investigations of topological phases in Josephson junctions.
- Future research can leverage this platform to explore novel quantum phenomena.
Related Concept Videos
01:27Biasing of Metal-Semiconductor Junctions
319
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
319
01:22Biasing of FET
352
Biasing a Junction Field Effect Transistor (JFET) is crucial for setting operational parameters and ensuring efficient functioning in electronic circuits. JFETs are characterized by using a single carrier type in N-channel or P-channel configurations, where the channel is surrounded by PN junctions. These junctions are central to the device's ability to control current flow.
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the...
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the...
352
01:22MOSFET: Enhancement Mode
451
Enhancement-mode MOSFETs are pivotal components in electronics, distinguished by their capacity to act as highly efficient switches. They are part of the larger family of metal-oxide Semiconductor Field-Effect Transistors (MOSFETs). They are available in two types: p-channel and n-channel, each tailored to specific polarity operations.
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no...
451
01:22Switching of BJT
487
Switching behavior in Bipolar Junction Transistors (BJTs) is a fundamental aspect utilized in various electronic circuits, particularly for digital logic applications like switches and amplifiers. In a typical switching circuit, a BJT alternates between cut-off and saturation modes, corresponding to the "off" and "on" states, respectively, thus behaving like an ideal switch.
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are...
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are...
487
01:21Characteristics of JFET
618
Junction Field Effect Transistors (JFETs) exhibit specific operational characteristics based on the relationship between the drain current (id) and the drain-source voltage (Vds), along with varying gate-source voltages (Vgs).
The core of a JFET's operation is controlling drain current by modulating the gate-source voltage. When the drain and gate voltage are set to zero, the JFET exhibits no net current flow, representing a state of equilibrium. The drain current increases linearly as the...
The core of a JFET's operation is controlling drain current by modulating the gate-source voltage. When the drain and gate voltage are set to zero, the JFET exhibits no net current flow, representing a state of equilibrium. The drain current increases linearly as the...
618
01:16Biasing of P-N Junction
772
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
772