High-fidelity quantum information transmission using a room-temperature nonrefrigerated lossy microwave waveguide

Area of Science:

• Quantum Information Science
• Quantum Optics
• Superconducting Quantum Computing

Background:

• Quantum microwave transmission is crucial for modular quantum computers and networks.
• Thermal noise in waveguides degrades quantum state fidelity, traditionally requiring refrigeration.
• Achieving high-fidelity transmission at room temperature is a significant challenge.

Purpose of the Study:

• To propose and analyze a novel method for high-fidelity quantum microwave transmission at room temperature.
• To overcome the limitations imposed by thermal noise in lossy waveguides.
• To enable practical implementation of quantum networks and distributed quantum computing.

Main Methods:

• Utilizing a room-temperature lossy microwave waveguide connecting cryogenic transmitter and receiver nodes.
• Implementing cryogenic preamplification before signal transmission.
• Employing a cryogenic loop antenna detector coupled to an LC harmonic oscillator at the receiver to suppress noise photons.

Main Results:

• The proposed scheme achieves high-fidelity quantum transmission (fidelity > [Formula: see text]) over 100 m.
• The loop antenna detector effectively suppresses induced noise photons across the LC oscillator.
• Significant preamplification gain maintains signal transmittance.

Conclusions:

• High-fidelity quantum microwave transmission is feasible without cryogenic waveguides.
• The developed method paves the way for practical room-temperature quantum communication systems.
• This breakthrough supports the development of scalable quantum computing and secure quantum networks.