All posts by cmeriles_1ry5wvws

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.

10-19: Mishkatul Bhattacharya from the Rochester Institute of Technology tells us about how to engineer a phonon laser

Mishkatul Bhattacharya

Optical Tweezer Phonon Laser

Abstract: We are in the middle of a revolution in phononics, where it seems useful and possible to control phonons as we have photons in the last few decades. In this talk
I will describe our theoretical proposal and its experimental demonstration regarding 
a phonon laser made of the center-of-mass oscillations of a nanoparticle trapped in an
optical tweezer.  I will report on threshold behavior, coherence, subthermal number 
squeezing, time dynamics, phase space characterization, injection locking, Q switching 
and the role of stimulated emission in our single mode phonon laser. Based on this discussion 
I will conclude that our device provides a pathway for engineering a coherent source of 
phonons on the mesoscale that can be applied to both fundamental problems in quantum 
mechanics as well as tasks of precision metrology.​

08-19: Jake’s and Daniela’s paper accepted in PNAS!

Optical spin pumping of color centers promises to revolutionize the practice of nuclear magnetic resonance via efficient dynamic nuclear polarization (DNP) protocols. Significant progress has been attained with systems such as the nitrogen-vacancy (NV) center in diamond, but extreme spectral broadening and nuclear spin-lattice relaxation from co-existing paramagnetic defects are hurdles still difficult to circumvent. The technique we present in this manuscript addresses both issues through the implementation of magnetic-field-sweep-induced NV cross-relaxation with ancilla point defects, here acting as proxies to mediate the transfer of polarization to the nuclear spin ensemble. The governing spin dynamics is robust to field misalignment and ideally suited for shallow NVs, indirectly coupled to outside nuclei through paramagnetic defects at the diamond surface.

06-19: We welcome Keishlyann Báez Cruz, our IDEALS-REU student guest this summer.

Keishlyann joins us this summer from the University of Puerto Rico at Mayagüez (UPRM), where she is majoring in Chemical Engineering with a certificate in Materials Science and Engineering. Her research experience includes prior work with Al alloys, and nanoporous metals under the supervision of Prof. O. Marcelo Suarez. Last year, she also joined the Material Advantage UPRM Chapter (the only materials sciences association in the Caribbean) where she conducted a number of activities aimed at increasing the enrollment of high-school students in STEM careers. We are very happy to have you here!