Here is a short video describing our work:

 
 

Our lab focuses on table top-scale experiments, developing new quantum tools for precision measurements and employing them to address key problems in fundamental and applied science. 

Diamonds

We use nitrogen-vacancy (NV) centers in diamond to perform magnetic imaging on the nanometer scale and study the fundamentals of statistical mechanics and many-body physics of interacting spin systems.

Dark MatTer

We are searching for dark matter, using precision nuclear magnetic resonance (NMR) techniques.

Experiments with Nitrogen-Vacancy (NV) color centers

applying quantum metrology to condensed matter and many-body physics

In recent years, quantum defects in diamond known as nitrogen vacancy (NV) color centers have attracted intense interest as precision quantum sensors with wide-ranging applications in both the physical and life sciences. This defect is formed by a nitrogen impurity next to a missing carbon, or vacancy, in the diamond lattice, and can be created naturally or by nitrogen ion implantation and annealing. The electrons occupying the dangling bonds around the vacancy play the role of the electrons bound to the nucleus of an atom or ion, exhibiting long-lived spin states and well-defined optical transitions. Despite the fact that the NV center is surrounded by carbon atoms only angstroms away, its states are so well isolated from environmental perturbations that their coherence properties can be comparable to those of an ion trapped in ultra-high vacuum, with the spin coherence lifetime reaching 1 ms.


We are exploring how to use NV centers as nanoscale sensors that can perform magnetic imaging of molecules and materials at nanometer length scales: a "nanoscale MRI machine". We apply a broad array of techniques developed in quantum information science to enhance the sensitivity, and temporal and spatial resolution of these sensors, and use them to address key problems in condensed matter and many-body physics.

Some of the laboratory techniques and concepts we use are: lasers, confocal microscopy, radiofrequency and microwave engineering, photolithography, chemistry, magnetic resonance, and quantum information science.

 

Cosmic Axion Spin Precession Experiment (CASPEr)

a laboratory table-top search for dark matter

The nature of dark matter is one of the most important open problems in modern physics. While the Weakly Interacting Massive Particle (WIMP) is a well motivated candidate, it is heavily constrained by null results from a variety of experiments, and the Large Hadron Collider has placed stringent constraints on scenarios such as supersymmetry that have provided the theoretical basis for WIMP dark matter. Thus, it is essential to develop techniques to search for a wide class of dark matter candidates, and axion dark matter stands out as being firmly based on theoretical foundations. A discovery of the axion would not only be the discovery of dark matter and a possible resolution of the strong CP problem of the Standard Model, but would also provide insights into the high-energy scales from which the axion arises, near the fundamental scales of particle physics such as the scale of grand unification and the Planck scale.

Remarkably, axion dark matter can have experimental signatures detectable in laboratory-scale low-energy precision experiments. The search strategy that we are exploring is based on spin precession caused by the background axion field, is sensitive to a wide range of axion masses, and has the potential to detect axion-like dark matter with coupling strength many orders of magnitude beyond the current astrophysical and laboratory limits, and all the way down to the Quantum Chromodynamics (QCD) axion.

Some of the laboratory techniques and concepts we use are: cryogenics (temperature down to 4 K), magnetic resonance, radiofrequency circuits, precision magnetic field sensors (eg, SQUIDs), superconducting magnets and magnetic shielding, low-noise analog and digital electronics, and lasers for optical pumping.

Have a look at the video below for a summary of our approach. Also, thanks to BU Today for putting together this article about our experiment.