Single-photon transistor using a Förster resonance

Area of Science:

• Quantum optics
• Atomic physics
• Quantum information science

Background:

• All-optical transistors offer potential for high-speed optical switching.
• Achieving high gain with minimal photon loss is crucial for practical applications.
• Rydberg excitations in ultracold gases provide a promising platform for quantum control.

Purpose of the Study:

• To investigate the quantum limit of an all-optical transistor.
• To demonstrate high gain and high fidelity switching using Rydberg excitations.
• To explore the potential for complex optical computations.

Main Methods:

• Utilizing ultracold atomic gases to store gate light pulses as Rydberg excitations.
• Employing Rydberg blockade enhanced by Förster resonance to control target light pulse transmission.
• Single-shot detection of transmitted photons to determine gate state.

Main Results:

• Observed a gain of 20 at the quantum limit of one incoming gate photon.
• Achieved single-shot detection fidelity above 0.86 for Rydberg excitation.
• Demonstrated suppression of target photon transmission via Rydberg blockade.

Conclusions:

• The demonstrated all-optical transistor operates at the quantum limit with significant gain.
• High fidelity single-shot readout is achievable, paving the way for quantum information processing.
• The high gain facilitates fan-out, enabling complex optical computational architectures.