Controllable Photonic Time-Bin Qubits from a Quantum Dot

Time-bin entangled photons from a quantum dot

Long-distance quantum communication is one of the prime goals in the field of quantum information science. With information encoded in the quantum state of photons, existing telecommunication fibre networks can be effectively used as a transport medium. To achieve this goal, a source of robust entangled single-photon pairs is required. Here we report the realization of a source of time-bin enta...

Time-bin entanglement with a single quantum dot

This thesis presents the development of an on-demand source of time-bin entangled photons, created from the biexciton-exciton radiative cascade in a single quantum dot. To achieve a source of time-bin entangled photons, we determined that the quantum dot must have two key properties: a dephasing time that is longer than the lifetime and high count rates, which are necessary to perform the corre...

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits.

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolari...

Solid State Spin-Wave Quantum Memory for Time-Bin Qubits.

We demonstrate the first solid-state spin-wave optical quantum memory with on-demand read-out. Using the full atomic frequency comb scheme in a Pr(3+):Y2SiO5 crystal, we store weak coherent pulses at the single-photon level with a signal-to-noise ratio >10. Narrow-band spectral filtering based on spectral hole burning in a second Pr(3+):Y2SiO5 crystal is used to filter out the excess noise crea...

Cross time-bin photonic entanglement for quantum key distribution