Optical Tweezers

Optical Tweezers Give Harvard Scientists the Control to Capture Ultracold Molecules

October 2, 2019

For most people, tweezers are a thing you’d find in a medicine cabinet or beauty salon, useful for getting rid of ingrown hairs or sculpting eyebrows.

Those designed by John Doyle and Kang-Kuen Ni have more exotic applications.

Using precisely focused lasers that act as “optical tweezers,” the pair have been able to capture and control individual, ultracold molecules — the eventual building-blocks of a quantum computer — and study the collisions between molecules in more detail than ever before. The work is described in a ...

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drawing of DNA of viruses

First Video of Viruses Assembling

September 30, 2019

For the first time, researchers have captured images of the formation of individual viruses, offering a real-time view into the kinetics of viral assembly. The research provides new insights into how to fight viruses and engineer self-assembling particles.

The research is published in the Proceedings of the National Academy of Sciences.*

"Structural biology has been able to resolve the structure of viruses with amazing resolution, down to every atom in every protein," said Vinothan Manoharan, the...

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optical dipole trap

An Optical Tweezer Array of Ultracold Molecules

September 13, 2019

Ultracold molecules have important applications that range from quantum simulation and computation to precision measurements probing physics beyond the Standard Model. Optical tweezer arrays of laser-cooled molecules, which allow control of individual particles, offer a platform for realizing this full potential. In a recent issue of Science, Harvard physics grad student Loïc Anderegg and colleaguesin Prof. John Doyle's group report on creating an optical tweezer array of laser-cooled calcium monofluoride molecules. This platform has also allowed scientists to observe ground-...

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architecture of the quantum convolutional neural networks

Quantum Convolutional Neural Networks

September 10, 2019

Machine learning techniques have so far proved to be very promising for the analysis of data in several fields, with many potential applications. However, researchers have found that applying these methods to quantum physics problems is far more challenging due to the exponential complexity of many-body systems. 

Quantum many-body systems are essentially microscopic structures made up of several interacting particles. While quantum physics studies have focused on the collective behavior of these systems, using machine learning in these investigations has proven to be very...

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Performance vs. Perception graph

Lessons in Learning

September 4, 2019

For decades, there has been evidence that classroom techniques designed to get students to participate in the learning process produces better educational outcomes at virtually all levels. And a new Harvard study suggests it may be important to let students know it.

The study, published Sept. 4 in the Proceedings of the National Academy of Sciences, shows that, though students felt as if they learned more through traditional lectures, they actually learned more when taking part in classrooms that employed so-called active-learning strategies. 

Lead author Louis...

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A plot of the electron spectral function for the important current-carrying electrons in energy-momentum space

Theory of a Planckian Metal

August 26, 2019

Graduate student Aavishkar Patel and Professor Subir Sachdev have recently presented a new theory of a Planckian metal that could shed light on previously unknown aspects of quantum physics. Their paper, published in Physical Review Letters, introduces a lattice model of fermions that describes a Planckian metal at low temperatures (T->0). 

Metals contain numerous electrons, which carry electric current. When physicists consider the electrical resistance of metals, they generally perceive it as arising when the flow of current-carrying electrons is...

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