Surface acoustic wave devices on bulk ZnO crystals at low temperature
Applied Physics Letters AIP Publishing 106:6 (2015) 063509-063509
Abstract:
Surface acoustic wave (SAW) devices based on thin films of ZnO are a well established technology. However, SAW devices on bulk ZnO crystals are not practical at room temperature due to the significant damping caused by finite electrical conductivity of the crystal. Here, by operating at low temperatures, we demonstrate effective SAW devices on the (0001) surface of bulk ZnO crystals, including a delay line operating at SAW wavelengths of λ = 4 and 6 μm and a one-port resonator at a wavelength of λ = 1.6 μm. We find that the SAW velocity is temperature dependent, reaching v ≈ 2.68 km/s at 10 mK. Our resonator reaches a maximum quality factor of Qi ≈ 1.5 × 105, demonstrating that bulk ZnO is highly viable for low temperature SAW applications. The performance of the devices is strongly correlated with the bulk conductivity, which quenches SAW transmission above 200 K.Quantum spin coherence in halogen-modified Cr7Ni molecular nanomagnets
Physical Review B American Physical Society (APS) 90:18 (2014) 184419
Magnetism in a family of $S = 1$ square lattice antiferromagnets Ni$X_2$(pyz)$_2$ ($X = $ Cl, Br, I, NCS; pyz = pyrazine)
(2014)
Quantum spin coherence in halogen-modified Cr$_7$Ni molecular nanomagnets
(2014)