QKD BB84 / E91 / MDI / CV; quantum teleportation; quantum repeaters; Holevo channel capacity; satellite-QKD Micius; quantum memory; no-cloning theorem; quantum internet roadmap; entanglement distribution.
Quantum Communication
QKD BB84 protocol
Bennett-Brassard 1984: 4-state non-orthogonal polarization protocol; security from no-cloning; Bennett-Bessette-Brassard-Salvail-Smolin…
QKD E91 (Ekert)
Ekert 1991: entanglement-based QKD using Bell-pairs; CHSH-violation security test detects eavesdropper; foundation for device-independent…
Quantum teleportation
Bennett-Brassard-Crepeau-Jozsa-Peres-Wootters 1993; first photon experiment Bouwmeester 1997; transfers unknown quantum state via shared…
Quantum repeater
Briegel-Dur-Cirac-Zoller 1998: chain of entanglement-purification + entanglement-swapping stations enables long-distance secure quantum…
Holevo channel capacity
Holevo 1973 / Schumacher-Westmoreland 1997 / Holevo 1998: classical capacity of quantum channel chi(rho) = S(sum p_i rho_i) - sum p_i…
Quantum internet
Wehner-Elkouss-Hanson 2018 6-stage roadmap: trusted-repeater to fault-tolerant Q-internet; QuTech Delft + Toshiba + Chinese demos;…
Satellite QKD (Micius)
Pan / Yin 2017 Micius satellite (CAS): 1200 km satellite-to-ground QKD; intercontinental Vienna-Beijing video call; current Eagle-1 ESA +…
Continuous-variable QKD
Grosshans-Grangier 2002 Gaussian-modulated-coherent-state QKD; uses homodyne detection vs single-photon detection; integrates with telecom…
MDI-QKD
Lo-Curty-Qi 2012: removes side-channel attacks on detectors via Bell-state measurement at untrusted central node; both Alice and Bob send…
Quantum memory (photonic)
Storage of photonic qubits in atomic ensembles (rubidium, cesium); EIT (electromagnetically-induced-transparency) Liu 2001 stopping light;…
No-cloning theorem (QKD basis)
Wootters-Zurek + Dieks 1982: arbitrary unknown quantum state cannot be cloned; provides operational basis for QKD security since…
Quantum key distribution overview
Shor-Preskill 2000 first composable security proof; ID Quantique + Toshiba + MagiQ commercial systems; current rate ~1 Mbps over 50 km; QKD…
BBM92 entanglement-based QKD
Bennett-Brassard-Mermin 1992: simplification of E91 using just two measurement-bases; security against eavesdropping via Bell-inequality…
Superdense coding (Bennett-Wiesner)
Bennett-Wiesner 1992: shared Bell-pair lets Alice transmit 2 classical bits via 1 qubit + 1 classical-bit of Pauli operation; demonstrates…
Decoy-state protocol (Hwang)
Hwang 2003 / Lo-Ma-Chen 2005: weak-coherent-pulse QKD vulnerable to PNS attack; using decoy intensity-states defeats PNS; foundation of…
Six-state QKD protocol
Bruss 1998: BB84 extended to 3 mutually-unbiased bases (X/Y/Z); each basis used 1/3 of time; tolerates higher QBER (12.6%) than BB84 (11%);…
Device-independent QKD (DIQKD)
Mayers-Yao 1998 / Acin 2007: security from Bell-inequality violation alone, without trusting devices; loophole-free Bell-test 2015 (Hensen)…
Quantum-internet router (store-and-forward)
Wehner-Elkouss-Hanson 2018 6-stage Q-internet roadmap: trusted-repeater -> measurement-only -> entanglement-routing -> quantum-routing ->…