Quantum Communication

Quantum Superposition

Quantum superposition allows particles to exist in multiple states simultaneously. This enables qubits to encode information beyond classical binary states, providing the basis for enhanced information processing and communication protocols.

Quantum Entanglement

Quantum entanglement links two or more particles such that their states remain correlated, even across large distances. By performing joint measurements, entanglement can be extended to previously independent particles, forming the foundation for scalable quantum networks and long-distance quantum communication.

Quantum Teleportation

Quantum teleportation transfers the state of a particle to a distant photon using an entangled pair and a Bell-state measurement. The measurement outcome is transmitted via a classical communication channel, allowing the receiver to reconstruct the original quantum state. This process enables quantum state transfer without physically sending the particle itself and is a key building block for future quantum networks.

Entanglement swapping

Entanglement swapping can be understood as a special case of quantum teleportation. Instead of transferring an arbitrary input state, the protocol effectively “teleports” one part of an entangled pair onto another photon. A Bell-state measurement on two photons from independent entangled pairs projects the remaining photons into an entangled state, even though they have never directly interacted. This mechanism is essential for extending entanglement across large distances in quantum networks.

PicoQuant provides advanced instrumentation designed to meet the demanding requirements of quantum communication and quantum key distribution experiments. Our technology enables precise timing, scalable data acquisition, and reliable synchronization for single-photon and entanglement-based protocols.

Key Advantages Include:

• Support for Advanced Encoding Protocols: High timing precision enables reliable time-bin, polarization, and entanglement-based encoding schemes.
• Remote and Multi-Device Synchronization: Precise synchronization across distributed nodes is enabled through technologies such as White Rabbit, allowing sub-nanosecond alignment for coincidence detection in scalable quantum communication networks.
• High-Speed Data Transfer: High-bandwidth USB interfaces and external FPGA interfaces enable real-time access to large time-tag data streams, supporting highest count rates and advanced post-processing in quantum communication experiments.
• Minimal Dead Time: The shortest dead times on the market minimize data loss and enable higher data transfer rates, even in demanding high-count-rate QKD setups.
• Low Timing Jitter and Photon Number Resolution (PNR): Ultra-low timing jitter is essential for fully exploiting superconducting nanowire single-photon detectors (SNSPDs). High timing resolution preserves temporal correlations and enables PNR in quantum communication experiments.