Low temperature dissipation scenarios in palladium nano-mechanical resonators

Abstract

We study dissipation in Pd nano-mechanical resonators at low temperatures in the linear response regime. Metallic resonators have shown characteristic features of dissipation due to tunneling two level systems (TLS). This system offers a unique tunability of the dissipation scenario by adsorbing hydrogen ($H_2$) which induces a compressive stress. The intrinsic stress is expected to alter TLS behaviour. We find a sub-linear power law $\sim T^{0.4}$ in dissipation. As seen in TLS dissipation scenarios we find a logarithmic increase of frequency characteristic from the lowest temperatures till a characteristic temperature $T_{co}$ is reached. In samples without $H_2$ the $T_{co}\sim 1K$ whereas with $H_2$ it is clearly reduced to $\sim 700mK$. Based on standard TLS phenomena we attribute this to enhanced phonon-TLS coupling in samples with compressive strain. We also find with $H_2$ there is a saturation in low temperature dissipation which may possibly be due to super-radiant interaction between TLS and phonons. We discuss the data in the scope of TLS phenomena and similar data for other systems.

References in corpus (17)

• Preparation and Detection of a Mechanical Resonator Near the Ground State of Motion
• Dynamical Backaction of Microwave Fields on a Nanomechanical Oscillator
• Single electron-phonon interaction in a suspended quantum dot phonon cavity
• Evidence for Quantized Displacement in Macroscopic Nanomechanical Oscillators
• Nanomechanical Detection of Itinerant Electron Spin Flip
• Surface dissipation in nanoelectromechanical systems: Unified description with the standard tunneling model and effects of metallic electrodes
• The "Tunneling Two-Level Systems" Model of the Low-Temperature Properties of Glasses: Are "Smoking-Gun" Tests Possible?
• Damping and decoherence of a nanomechanical resonator due to a few two level systems
• Dissipation due to tunneling two-level systems in gold nanomechanical resonators
• Damping in high-frequency metallic nanomechanical resonators
• Strong gate coupling of high-Q nanomechanical resonators
• Strain-Induced Coupling of Spin Current to Nanomechanical Oscillations
• Quantum Friction of Micromechanical Resonators at Low Temperatures
• Diffusion-induced bistability of driven nanomechanical resonators
• Why Study Noise due to Two Level Systems: A Suggestion for Experimentalists
• Evidence for the role of normal-state electrons in nanoelectromechanical damping mechanisms at very low temperatures
• How Stress Can Reduce Dissipation in Glasses

Cited by in corpus (2)

• Temperature Dependent Non-linear Damping in Palladium Nano-mechanical Resonators
• Dimensional control of tunneling two level systems in nanoelectromechanical resonators