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This brief presents a high-voltage RF source for trapped-ion quantum computing. It consists of an external transformer and a driver implemented on a single chip. The use of a transformer significantly reduces on-chip current driving requirements to 32mA while delivering a 620-VPP to the output. The proposed architecture also achieves a 20dB improvement in SFDR compared to the previous work. This brief includes a guide for the optimal transformer design that can maximize the output voltage with the minimum power consumption. The proposed design scheme provides a miniaturized implementation of the RF source and makes it promising for scalable quantum computing with multiple RF sources.

A novel approach to fabricate polymer brushes on the surface of carbon nanotubes (CNTs) is proposed. Carboxyl groups on the surface of chemically oxidized CNTs were reacted with hexamethylene diisocyanate, followed by a reaction with methacrylamide to give terminal vinyl groups‐functionalized CNTs, so called “CNT‐mer.” The synthetic procedure was investigated step‐by‐step and the synthesized CNT‐mer was used to grow polystyrene (PS) from CNTs by a simple in situ polymerization in the presence of a thermal initiator. By employing 1H NMR, X‐ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and light scattering, the experimental results were verified. Using this approach, 45% PS with respect to CNTs are grafted on the surface of CNTs with about 4.0 nm thickness. This novel technique would provide a facile route to prepare tailor‐made polymer brushes on the surface of CNTs. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44:6394–6401, 2006