Related Experiment Video
Updated: Dec 15, 2025
11:33
All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
10.1K
Suppressed Charge Dispersion via Resonant Tunneling in a Single-Channel Transmon
A Kringhøj1, B van Heck2,3, T W Larsen1
1Microsoft Quantum Lab Copenhagen and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
Physical Review Letters
|July 9, 2020
Summary
We reduced charge dispersion in semiconductor transmon qubits using quantum dots. This breakthrough offers improved qubit performance for quantum computing applications.
Area of Science:
- Quantum Computing
- Solid-State Physics
- Superconducting Qubits
Background:
- Transmon qubits are essential for quantum computing.
- Charge dispersion affects qubit coherence and performance.
- Quantum dots offer novel ways to engineer qubit properties.
Purpose of the Study:
- To suppress charge dispersion in transmon qubits.
- To investigate the effect of quantum dots in Josephson junctions.
- To develop a model for qubit dispersion.
Main Methods:
- Fabrication of semiconductor-based transmon qubits with quantum dots in the Josephson junction.
- Experimental measurement of qubit dispersion across Josephson resonances.
- Development of a theoretical model for qubit dispersion.
Main Results:
- Strong suppression of charge dispersion was achieved.
- Dispersion was significantly reduced on resonance compared to conventional transmons.
- The developed model quantitatively matched experimental data.
Conclusions:
- Quantum dots in Josephson junctions effectively suppress charge dispersion.
- This method enhances transmon qubit performance.
- The findings pave the way for more robust quantum computing.
Related Concept Videos
01:20MOSFET: Depletion Mode
721
Depletion-mode MOSFETs represent a unique subset of MOSFET technology, functioning fundamentally differently from their enhancement-mode counterparts. Unlike enhancement MOSFETs, which require a positive gate-source voltage (Vgs) to turn on, depletion-mode MOSFETs are inherently conductive and "normally on" devices.
The primary characteristic of depletion-mode MOSFETs is their ability to conduct current between the drain and source terminals without gate bias. This inherent conductivity...
The primary characteristic of depletion-mode MOSFETs is their ability to conduct current between the drain and source terminals without gate bias. This inherent conductivity...
721
01:23Parallel Resonance
426
The parallel RLC circuit is an arrangement where the resistor (R), inductor (L), and capacitor (C) are all connected to the same nodes and, as a result, share the same voltage across them. The parallel RLC circuit is analyzed in terms of admittance (Y), which reflects the ease with which current can flow. The admittance is given by:
426
01:22MOSFET: Enhancement Mode
679
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...
679
01:12Double Resonance Techniques: Overview
581
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
581
01:25MOS Capacitor
1.3K
A Metal-Oxide-Semiconductor (MOS) capacitor is a fundamental structure used extensively in semiconductor device technology, particularly in the fabrication of integrated circuits and MOSFETs (metal-oxide-semiconductor field-effect transistors). The MOS capacitor consists of three layers: a metal gate, a dielectric oxide, and a semiconductor substrate.
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
1.3K
01:24Metal-Semiconductor Junctions
767
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
767