Searching for the Casimir Energy

Abstract

In this article, we present a nano-electromechanical system (NEMS) designed to detect changes in the Casimir Energy. The Casimir effect is a result of the appearance of quantum fluctuations in the electromagnetic vacuum. Previous experiments have used nano- or micro- scale parallel plate capacitors to detect the Casimir force by measuring the small attractive force these fluctuations exert between the two surfaces. In this new set of experiments, we aim to directly detect shifts in the Casimir $\text{energy}$ in the vacuum due to the presence of metallic parallel plates, one of which is a superconductor. A change in the Casimir energy of this configuration is predicted to shift the superconducting transition temperature (T${}_{\text{c}}$) because of an interaction between it and the superconducting condensation energy. The experiment we discuss consists of taking a superconducting film, carefully measuring its transition temperature, bringing a conducting plate close to the film, creating a Casimir cavity, and then measuring the transition temperature again. The expected shifts will be small, comparable to the normal shifts one sees in cycling superconducting films to cryogenic temperatures and so using a NEMS resonator and doing this in situ is the only practical way to obtain accurate, reproducible data. Using a thin Pb film and opposing Au surface, we observe no shift in T${}_{\text{c}}$ greater than 12 $\mu$K down to a minimum spacing of approximately 70 nm.

References in corpus (5)

• Measurement of non-monotonic Casimir forces between silicon nanostructures
• Design of a Casimir-driven parametric amplifier
• Low noise cryogenic system for the measurement of Casimir energy in rigid cavities
• Searching for the Casimir Energy
• Atomic Calligraphy: The Direct Writing of Nanoscale Structures using MEMS

Cited by in corpus (3)

• Strong geometry dependence of the Casimir force between interpenetrated rectangular gratings
• Searching for the Casimir Energy
• Proposal to measure the Casimir Effect Across the Superconducting Transition