Related Experiment Video
Updated: Aug 10, 2025
15:47
Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
Published on: November 1, 2013
16.4K
99.92%-Fidelity cnot Gates in Solids by Noise Filtering
Tianyu Xie1,2, Zhiyuan Zhao1,2, Shaoyi Xu1,2
1CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China.
Physical Review Letters
|February 10, 2023
Summary
We achieved a 99.920(7)% fidelity controlled-not gate in solid-state spin systems by developing a complete noise model and using shaped pulses for dynamic error correction, overcoming previous limitations.
Area of Science:
- Quantum Information Science
- Solid-State Physics
- Quantum Computing
Background:
- Entangling gates are crucial for quantum computation but are degraded by environmental noise.
- Previous fidelity limitations were due to incomplete noise models considering only static classical noise.
Purpose of the Study:
- To experimentally demonstrate a high-fidelity controlled-not (CNOT) gate in a solid-state spin system at room temperature.
- To overcome performance degradation caused by reservoir interactions and complex noise.
Main Methods:
- Constructed a comprehensive noise model including time-dependent and quantum spin bath interactions.
- Employed exquisitely designed shaped pulses for dynamic correction of all identified noise sources.
- Utilized a solid-state spin system at room temperature for experimental demonstration.
Main Results:
- Achieved a record 99.920(7)% fidelity for the controlled-not gate.
- Reduced gate error below 10^{-4} by dynamically correcting complex noise.
- Identified longitudinal relaxation and waveform distortion as key residual error sources.
Conclusions:
- A universal, noise-resistant method for high-fidelity quantum gates has been demonstrated.
- The developed technique significantly advances the feasibility of practical quantum computation.
- The method is applicable to various solid-state spin systems, promising broad impact.
Related Concept Videos
01:22Biasing of FET
339
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...
339
01:23Small-Signal Analysis of MOSFET Amplifiers
641
In small-signal analysis, a MOSFET transistor amplifier acts as a linear amplifier when operating in its saturation region. The gate-to-source voltage (VGS) of the MOSFET is the sum of the DC biasing voltage and the small time-varying input signal. This combination sets up the operating point and modulates the drain current (ID) that flows from the drain to the source. When a small AC signal is superimposed on the DC bias voltage at the gate, the instantaneous drain current comprises three...
641
01:27Biasing of Metal-Semiconductor Junctions
302
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...
302
01:29Field Effect Transistor
505
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...
505
01:14NMR Spectrometers: Resolution and Error Correction
749
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
749
01:22MOSFET: Enhancement Mode
424
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...
424