Related Experiment Video
Updated: Jan 26, 2026
07:56
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
8.9K
On-Demand Semiconductor Source of Entangled Photons Which Simultaneously Has High Fidelity, Efficiency, and
Hui Wang1,2, Hai Hu3, T-H Chung1,2
1Shanghai Branch, National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Shanghai 201315, China.
Physical Review Letters
|April 6, 2019
Summary
Researchers developed a quantum dot source for single entangled photon pairs, achieving high fidelity and efficiency. This breakthrough advances quantum optics and scalable photonic quantum technology for future applications.
Area of Science:
- Quantum Optics
- Solid-State Quantum Technology
- Photonic Quantum Information
Background:
- Scalable photonic quantum technology requires sources emitting single entangled photon pairs.
- High entanglement fidelity, extraction efficiency, and photon indistinguishability are crucial for such sources.
Purpose of the Study:
- To develop a quantum light source for single entangled photon pairs.
- To achieve high performance in entanglement fidelity, extraction efficiency, and photon indistinguishability simultaneously.
Main Methods:
- Utilized coherent two-photon excitation.
- Employed a single Indium Gallium Arsenide (InGaAs) quantum dot coupled to a circular Bragg grating bull's-eye cavity.
- Leveraged a broadband high Purcell factor (up to 11.3).
Main Results:
- Generated entangled photon pairs with a state fidelity of 0.90(1).
- Achieved a pair generation rate of 0.59(1) and pair extraction efficiency of 0.62(6).
- Demonstrated photon indistinguishability of 0.90(1) simultaneously.
Conclusions:
- The developed quantum dot source meets the outstanding goals in quantum optics.
- This technology paves the way for high-efficiency multiphoton experiments.
- Enables advancements in solid-state quantum repeaters.
Related Concept Videos
01:22Semiconductors
1.4K
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
1.4K
01:20Types of Semiconductors
1.4K
Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
1.4K
01:24Metal-Semiconductor Junctions
944
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...
944
01:27Biasing of Metal-Semiconductor Junctions
566
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...
566
01:18Sinusoidal Sources
1.1K
Direct current (DC) refers to an electric current that flows in a single direction, maintaining a constant polarity. This is in contrast to alternating current (AC), which periodically changes its direction and magnitude. AC forms the backbone of modern electricity transmission and distribution systems due to its efficient long-distance transmission capabilities.
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
1.1K
01:15Source Transformation
11.3K
Source transformation is a fundamental technique employed in circuit analysis, offering a valuable tool for simplifying complex electrical circuits. This technique involves the replacement of either a voltage source in series with a resistor by a current source in parallel with a resistor, or vice versa. The key concept here is that when the original sources are deactivated (turned off), the equivalent resistance at the circuit's end terminals remains the same.
It is essential to note that when...
It is essential to note that when...
11.3K