Prof Arzhang Ardavan

Abstract:

The synthesis, isolation and characterization of a previously undiscovered bimetallic endohedral fullerene, PrSc@C80, are presented, and this may pave the way for a whole family of bimetallic endohedral fullerenes in useful quantities.

Abstract:

Photoluminescence spectroscopic measurements have allowed the acquisition of high resolution spectra at low temperature for the endohedral metallofullerenes, Er2 @ C82 (isomer I) and Er2 C2 @ C82 (isomer I). The characteristic emission in the 1.5-1.6 μm region corresponds to the 4 I13 / 2 (m) → 4 I15 / 2 (n) transitions of the Er3 + ion for both molecules. The emission arising from Er2 C2 @ C82 (I) appears acuminated (narrow lines that taper to a point) when compared with that of Er2 @ C82 (I). The Er2 C2 @ C82 (I) emission linewidths are comparable to those found in crystals, making this molecule of interest for applications where accessible, well-defined quantum states are required. © 2009 Elsevier B.V. All rights reserved.

Abstract:

Quantum entangled states can be very delicate and easily perturbed by their external environment. This sensitivity can be harnessed in measurement technology to create a quantum sensor with a capability of outperforming conventional devices at a fundamental level. We compared the magnetic field sensitivity of a classical (unentangled) system with that of a 10-qubit entangled state, realized by nuclei in a highly symmetric molecule. We observed a 9.4-fold quantum enhancement in the sensitivity to an applied field for the entangled system and show that this spin-based approach can scale favorably as compared with approaches in which qubit loss is prevalent. This result demonstrates a method for practical quantum field sensing technology.