Quantum mechanics

Repeater (horology)

Quantum computer

Quantum key distribution

Engineering

Construct (python library)

Materials science

Coherence (philosophical gambling strategy)

Operating system

Telecommunications

Scalability

Computer science

Modular design

Computer network

Photonics

Physics

Database

Quantum network

Quantum memory

Electronic engineering

Artificial intelligence

Quantum

Composite material

Fiber

Transmission (telecommunications)

Encoding (memory)

Optoelectronics

Advanced Quantum Technologies

Elementary building blocks for quantum repeaters based on fiber channels and memory stations are analyzed. Implementations are considered for three different physical platforms, for which suitable components are available: quantum dots, trapped atoms and ions, and color centers in diamond. The performances of basic quantum repeater links for these platforms are evaluated and compared, both for present‐day, state‐of‐the‐art experimental parameters as well as for parameters that can in principle be reached in the future. The ultimate goal is to experimentally explore regimes at intermediate distances—up to a few 100 km—in which the repeater‐assisted secret key transmission rates exceed the maximal rate achievable via direct transmission. Two different protocols are considered, one of which is better adapted to the higher source clock rate and lower memory coherence time of the quantum dot platform, while the other circumvents the need of writing photonic quantum states into the memories in a heralded, nondestructive fashion. The elementary building blocks and protocols can be connected in a modular form to construct a quantum repeater system that is potentially scalable to large distances.

Extending Quantum Links: Modules for Fiber‐ and Memory‐Based Quantum Repeaters