In this seminar we will hear from two of our PhD students – Ruvi Lecamwasam and Hao Jeng – from ANU presenting their latest research.
Research Overview: How your choice of measurement basis bounds estimator error – answers using entropy and circular statistics
Speaker: Ruvi Lecamwasam, ANU
Research overview: Teleporting coherent states of photons with reduced decoherence
Speaker: Hao Jeng, ANU
Quantum teleportation of a coherent state causes it to evolve from a superposition of Fock states into a statistical mixture. The extent to which this occurs depends on the amount of decoherence introduced by the teleporter which must be kept to a minimum. Fidelities from the best attempts have been found to cap at about 83%, limited by the unavoidable loss of photons which is the source of decoherence in these experiments. Thus there has been considerable interest in devising schemes for mitigating decoherence, relying on techniques such as entanglement distillation and quantum error correction. However, implementations of these complex schemes are challenging and no successful attempt has yet been reported. Here we show that coherent states can be teleported with reduced decoherence. By implementing noiseless linear amplification in a quantum teleporter, we observed a marked increase in fidelities, obtaining values of about 92%. Furthermore, we found that noiseless linear amplification — unlike other methods — is readily accessible as it does not require any components that is not already present in the teleporter. These results indicate that the effects of photon loss due to teleportation can be reversed without the use of quantum error correction or entanglement distillation, providing an alternative method for reducing the decoherence of quantum systems.
Speaker: Ruvi Lecamwasam & Hao Jeng
Date: September 29 @ 2:00 pm - 3:00 pm
Event Category: Seminar
Authors Centre Participants: Mr. Ruvindhra Lecamwasam, Mr. Hao Jeng