Laser cooling of a nanomechanical oscillator into its quantum ground state

A patterned Si nanobeam is formed which supports co-localized acoustic and optical resonances that are coupled via radiation pressure. Starting from a bath temperature of T=20K, the 3.68GHz nanomechanical mode is cooled into its quantum mechanical ground state utilizing optical radiation pressure. The mechanical mode displacement fluctuations, imprinted on the transmitted cooling laser beam, indicate that a final phonon mode occupancy of 0.85 +-0.04 is obtained.Comment: 18 pages, 10 figure

Microstrip resonators for electron paramagnetic resonance experiments

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5x10(10) spins/GHz(1/2) despite the low MR unloaded quality factor Q(0)=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.807Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)SPM Brazil networkConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)HP-BrazilCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)IEEE MTT-SFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [04/01228-6

Optomechanical Crystal Devices

We present the basic ideas and techniques utilized in recent work on optomechanical crystals. Optomechanical crystals are nanofabricated cavity optomechanical systems where the confinement of light and motion is obtained by nanopatterning periodic structures in thin-films. In this chapter we start from a basic review of the properties of optical and elastic waves in nanostructures, before introducing the properties and design of periodic structures. After reviewing fabrication and characterization methods, experimental results in 1D and 2D systems are presented