Category: Group Publication

Measuring entanglement without destroying it on commercial quantum computers

Group Publication

In quantum mechanics, the act of measurement produces unavoidable perturbation (also called “back-action”) on the state of the measured system. This effect is, in many cases, not desirable, as back-action often limits the precision of repeated measurements. However, so-called Quantum Non-Demolition (QND) measurements ensure that the unavoidable and deleterious back-action is diverted onto other system (…)

Molecular device turns infrared into visible light

Group Publication

Our group, in collaboration with Wuhan Institute of Technology, the Valencia Polytechnic University, and AMOLF in the Netherlands, has now developed a new way to detect infrared light by changing its frequency to that of visible light. The device can extend the “sight” of commonly available and highly sensitive detectors for visible light far into (…)

Green light on gold atoms

Group Publication

Our group discovered that laser-driven rearrangement of just a few gold atoms inside nanoscale antennas can be observed by the naked eye. Because individual atoms or molecules are 100 to 1000 times smaller than the wavelength of visible light, it is notoriously difficult to collect information about their dynamics, especially when they are embedded within (…)

Molecular Adlayer and the Stability of Nanoparticle-on-Mirror Plasmonic Cavities

Group Publication

Immense field enhancement and nanoscale confinement of light are possible within nanoparticle-on-mirror (NPoM) plasmonic resonators, which enable novel optically activated physical and chemical phenomena and render these nanocavities greatly sensitive to minute structural changes, down to the atomic scale. Although a few of these structural parameters, primarily linked to the nanoparticle and the mirror morphology, (…)

When light and atoms share a common vibe

Group Publication

Our group with collaboration with MIT and CEA Saclay demonstrate a state of vibration that exists simultaneously at two different times. They evidence this quantum superposition by measuring the strongest class of quantum correlations between light beams that interact with the vibration. An especially counter-intuitive feature of quantum mechanics is that a single event can (…)

Lighting the way to infrared detection

Group Publication

Philippe Roelli proposes a new path to detect infrared radiation with outstanding sensitivity, allowing detection of signals as low as that of a single quantum of light. The related publication can be found in Physical Review X.  When using our webcam or cell phone camera, we experience the tremendous capabilities of cheap and compact sensors (…)

Time-resolved Bell Correlation Spectroscopy of Molecular Vibrations

Group Publication

Our group has performed the first measurement of Bell correlations between light and a collective molecular vibration in a diamond crystal. Our results are now accessible on the arXiv.

Observation of a single quantum of vibrational energy at ambient conditions

Group Publication

Our group has for the first time successfully observed a single quantum of vibrational energy at ambient conditions, involving the oscillation of more than 100 billion atoms in a diamond crystal. Our work is now published in Physical Review X, and highlighted on EPFL and MIT websites. Check it out! Original article in Physical Review X (…)

Detecting the birth and death of a single phonon

Group Publication

Our latest results on single phonon Fock state generation are now published on the arXiv and were submitted for peer-review! This is the first direction demonstration that a single quantum of vibrational energy can be excited and prepared using a projective measurement on the quantum-correlated Stokes photon. This work was performed in collaboration with Dr. Vivishek Sudhir (…)

Internal vibrations mediate quantum correlations

Group Publication

Our group has developed a new technique to probe elementary quantum excitations of atomic vibrations inside a crystal under ambient conditions. The technique uses ultra-short laser pulses and detectors sensitive to single photons. This work was performed in collaboration with the Laboratory of Theoretical Physics of Nanosystems at EPFL and Nicolas Sangouard at the Quantum Optics Theory Group in (…)