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Published on: May 30, 2014
Differential-phase-shift quantum key distribution using heralded narrow-band single photons.
Chang Liu1, Shanchao Zhang, Luwei Zhao
1Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Optics Express
|April 24, 2013
Summary
This study shows the first differential phase shift (DPS) quantum key distribution (QKD) using single photons. Narrow-band photons achieved low quantum bit error rates (QBER), meeting security needs for quantum communication.
Area of Science:
- Quantum Information Science
- Quantum Cryptography
- Photonics
Background:
- Quantum Key Distribution (QKD) enables secure communication through quantum mechanics.
- Differential Phase Shift (DPS) QKD is a promising protocol for secure key exchange.
- Heralded single photons are crucial for reliable quantum optical experiments.
Purpose of the Study:
- To demonstrate the first proof of principle for DPS-QKD using narrow-band heralded single photons.
- To investigate the impact of amplitude-phase modulations on DPS-QKD performance.
- To assess the trade-off between key creation efficiency and quantum bit error rate (QBER) in DPS-QKD.
Main Methods:
- Utilized narrow-band heralded single photons with amplitude-phase modulations for DPS-QKD.
- Experimentally implemented the DPS-QKD protocol with varying numbers of pulses.
- Measured quantum bit error rate (QBER) and key creation efficiency.
Main Results:
- Achieved a QBER as low as 3.06% in the 3-pulse case, satisfying unconditional security requirements.
- Observed key creation efficiency approaching 93.4% with 15 pulses.
- Demonstrated a trade-off where increasing pulse number enhances efficiency but also increases QBER.
Conclusions:
- Narrow-band heralded single photons are a viable and promising source for DPS-QKD protocols.
- The demonstrated DPS-QKD system offers a potential pathway towards practical quantum communication.
- Amplitude-phase modulations are effective for implementing DPS-QKD with single photons.
