Ruby A. Lai '12: The Bends, Nano-Style

To properly store her delicate samples of carbon nanotubes, Ruby A. Lai ’12 spent her hot summer in Cambridge fixing a helium fridge that could cool the temperature down to a few hundredths of a degree above absolute zero.

The Chemistry and Physics concentrator has been working at the Harvard Marcus Lab since sophomore year to study carbon nanotubes, which are long, thin fibers of carbon atoms arranged in hexagonal patterns. Much “fundamental physical research” has been performed about nanotubes, which were first synthesized about a decade ago, according to Lai.

The researchers in the Marcus Lab are working to find a way to use the two spin directions of electrons in the nanotubes to encode information. Such a development would mark an important step toward the making of quantum computers.

Lai said that the researchers must overcome the difficulty of capturing an electron’s spin in the nanotubes—a task that her lab’s principal investigator, Charles M. Marcus, had hypothesized last year could be made possible by manipulating bends into the carbon cylinders.

A bend in the cylinder introduces a rapid change to the magnetic field that runs along the nanotube and may be used to manipulate electron spins, according to Lai.

“It’s a very new idea, and nobody’s ever done experimental studies on nanotube bends and how they behave electrically,” she said.

Lai’s experiments will be the first to characterize the effects of the bend and to determine the differences between bent and straight nanotubes. She said that she hopes to discover whether the bends have as great of a potential as hypothesized.

“Everything is in theory land right now, and we’re all just waiting for the first experiment,” said Marcus, a professor of physics. “I think [Lai’s] experiment can have a big impact.”

Lai first became interested in nanotubes and graphene—the research subject of the winners of the Nobel Prize in Physics this year—through her freshman seminar called “Molecular Motors: Wizards of the Nanoworld,” led by Professor Emeritus Dudley R. Herschbach, who won the 1986 Nobel Prize in Chemistry.

“During my freshman year, graphene research was really cutting edge,” Lai said. “I was really inspired by a presentation that I worked on.”

—Staff writer Helen X. Yang can be reached at hxyang@fas.harvard.edu.

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