Shining a Light on Quantum Bits

January 31, 2019

Credit: Denis Sukachev

In the world of quantum computing, interaction is everything. For computers to work at all, bits — the ones and zeros that make up digital information — must be able to interact and hand off data for processing. The same goes for the quantum bits, or qubits, that make up quantum computers.

But that interaction creates a problem — in any system in which qubits interact with each other, they also tend to want to interact with their environment, resulting in qubits that quickly lose their quantum nature.


A Quantum Science Initiative at Harvard

November 14, 2018

A panoramic shot of the Advanced Cold Molecule Electron EDM, a device in the laboratory of Silsbee professor of physics John Doyle that is designed to make measurements of the quantum physical behavior of electrons so precise that the results could change understanding of the Standard Model of quantum physics. [Photograph courtesy of John Doyle/Harvard Research Center for Quantum Optics.]


Sending Spin Waves into an Insulating 2D Magnet

November 9, 2018

Researchers excited and detected spin waves in a quantum Hall ferromagnet, spending them through the insulating material like waves in a pond. (Image courtesy of Second Bay Studios/Harvard SEAS)

Quantum Hall ferromagnets are among the purest magnets in the world — and one of the most difficult to study. These 2D magnets can only be made in temperatures less than a degree above absolute zero and in high magnetic fields, about the scale of an MRI.


Origin of Mott Insulating Behavior and Superconductivity in Twisted Bilayer Graphene

October 2, 2018

Fig. 5. Localization of the other set of constructed Wannier functions.*

In the last few months, researchers have discovered that twisted bilayer graphene—two sheets of graphene layered at a slight angle to one another—can behave as either a superconductor or a type of insulator. An exciting aspect of this realization is that the behavior is selectable: By simply changing an applied voltage, it is possible to go from insulator to superconductor and back.