All posts by cmeriles_1ry5wvws

11-20: Hari’s paper on charge-based storage of spin state accepted in Phys. Rev. Lett. Congratulations to Hari and his co-authors!

We articulate confocal microscopy and electron spin resonance to implement spin-to-charge conversion in a small ensemble of nitrogen-vacancy (NV) centers in bulk diamond, and demonstrate charge conversion of neighboring defects conditional on the NV spin state. We build on this observation to show time-resolved NV spin manipulation and ancilla-charge-aided NV spin state detection via integrated measurements. Our results hint at intriguing opportunities in the development of novel measurement strategies in fundamental science and quantum spintronics as well as in the search for enhanced forms of color-center-based metrology down to the limit of individual point defects.

11-20: Artur’s paper on space charge accepted in Physical Review Letters, way to go!

While the study of space charge potentials has a long history, present models are largely based on the notion of steady state equilibrium, ill-suited to describe wide-bandgap semiconductors with moderate to low concentrations of defects. Here we build on color centers in diamond both to locally inject carriers into the crystal and probe their evolution as they propagate in the presence of external and internal potentials. We witness the formation of metastable charge patterns whose shape — and concomitant field — can be engineered through the timing of carrier injection and applied voltages. With the help of previously crafted charge patterns, we unveil a rich interplay between local and extended sources of space charge field, which we then exploit to show space-charge-induced carrier guiding.

08-20: BNL designated a Quantum Information Science research center. CCNY joins in as a partner.

The U.S. Department of Energy (DOE) Office of Science has selected Brookhaven National Laboratory to lead the Co-design Center for Quantum Advantage (C2QA), which will focus on quantum computing. The goal is to achieve quantum advantage in computations for high-energy and nuclear physics, chemistry, materials science, condensed matter physics, and other fields. Overseeing C2QA are Steve Girvin, professor at Yale University, and James Misewich, associate laboratory director for Energy and Photon Sciences at Brookhaven.

The partnering institutions on C2QA are Ames Laboratory, Caltech, City College of New York, Columbia University, Harvard University, Howard University, IBM, Johns Hopkins University, MIT, Montana State University, National Aeronautics and Space Administration’s Ames Research Center, Northwestern University, Pacific Northwest National Laboratory, Princeton University, State University of New York Polytechnic Institute, Stony Brook University, Thomas Jefferson National Accelerator Facility, University of California-Santa Barbara, University of Massachusetts-Amherst, University of Pittsburgh, University of Washington, Virginia Tech, and Yale University.

Additional information on the role of CCNY can be found here.

04-20: Gabriel’s paper selected for OSA Spotlight!

Spotlight Summary by Igor Aharonovich

Room-temperature single photon emitters in cubic boron nitride nanocrystals

Find more information here.

03-20: Gabriel’s paper on color centers in cubic boron nitride chosen for the cover of OMEX. Congrats!

Color centers in wide bandgap semiconductors are attracting broad attention for use as platforms for quantum technologies relying on room-temperature single-photon emission (SPE), and for nanoscale metrology applications building on the centers’ response to electric and magnetic fields. Here, we demonstrate room-temperature SPE from defects in cubic boron nitride (cBN) nanocrystals, which we unambiguously assign to the cubic phase using spectrally resolved Raman imaging. These isolated spots show photoluminescence (PL) spectra with zero-phonon lines (ZPLs) within the visible region (496–700 nm) when subject to sub-bandgap laser excitation. Second-order autocorrelation of the emitted photons reveals antibunching with g2(0) ∼ 0.2, and a decay constant of 2.75 ns that is further confirmed through fluorescence lifetime measurements. The results presented herein prove the existence of optically addressable isolated quantum emitters originating from defects in cBN, making this material an interesting platform for opto-electronic devices and quantum applications.