arXiv subjects

Gabriel Hétet

Publications and source records attributed to Gabriel Hétet.

15 recordsLinked to original sources

arXiv2026

High-Sensitivity Optical Detection of Electron-Nuclear Spin Clusters in Diamond

We perform sensitive nuclear magnetic resonance (NMR) with spin ensembles which are polarized by nitrogen vacancy centers (NV centers) in diamond at room-temperature. With a near shot-noise-limited photoluminescence detection and a highly uniform magnetic field, we resolve sharp NMR features arising from multiple spin clusters. In particular, we investigate the coupling between nuclear spins and NV centers in the neutral and negatively charged states. Further, we perform high precision NMR and coherent control of families of carbon 13 nuclear spin ensembles in the $m_s$=0 level of the NV ground state. Applying an off-axis magnetic field reveals the various sites associated with the otherwise degenerate couplings of the carbon 13 sites around the NV electronic spin providing access to all the hyperfine tensor components. Last, we observe spectroscopic signatures of pairs of nuclear spins coupled to the same NV center. These results are relevant for ensemble measurements of dynamical polarization that currently rely on expensive nuclear magnetic resonance systems as well as for recently proposed nuclear spin gyroscopes.

quant-ph↗

arXiv2026

Gyroscopically stabilized quantum spin rotors

Recent experiments demonstrate all-electric spinning of levitated nanodiamonds with embedded nitrogen-vacancy spins. Here, we argue that such gyroscopically stabilized spin rotors offer a promising platform for probing and exploiting quantum spin-rotation coupling of particles hosting a single spin degree of freedom. Specifically, we derive the effective Hamiltonian describing how an embedded spin affects the rotation of rapidly revolving quantum rotors due to the Einstein-de Haas and Barnett effects, which we use to devise experimental protocols for observing this coupling in state-of-the-art experiments. This will open the door for future exploitations of quantum spin rotors for superposition experiments with massive objects.

quant-ph↗

arXiv2025

Spin-dependent Force from an NV center Ensemble on a Microlever

We report the observation of spin-dependent force induced by Nitrogen Vacancy (NV) centers embedded in a diamond crystal attached to a tethered oscillator. This result was obtained using a spin-dependent torque generated by a micro-diamond containing billions of NV centers, placed at the end of a commercially available silicon cantilever. %We demonstrate that the fundamental flexural mode of the cantilever is excited by the spins of the NV centers. These spins are uniformly coupled to an externally applied homogeneous magnetic field, which enables the NV centers to exert a measurable spin-dependent torque on the cantilever, driving its center of mass motion. Our experiment highlights the intricate interplay between the spin properties of NV centers and the mechanical behavior of the oscillator in the presence of a pure torque, providing a set of tools for exploring quantum effects in state of the art micro-mechanical systems.

quant-ph↗

arXiv2023

Spin Read-out of the Motion of Levitated Electrically Rotated Diamonds

Recent advancements with trapped nano- and micro-particles have enabled the exploration of motional states on unprecedented scales. Rotational degrees of freedom stand out due to their intrinsic non-linearity and their coupling with internal spin degrees of freedom, opening up possibilities for gyroscopy and magnetometry applications and the creation of macroscopic quantum superpositions. However, current techniques for fast and reliable rotation of particles with internal spins face challenges, such as optical absorption and heating issues. Here, to address this gap, we demonstrate electrically driven rotation of micro-particles levitating in Paul traps. We show that micro-particles can be set to rotate stably at 150,000 rpm by operating in a hitherto unexplored parametrically driven regime using the particle electric quadrupolar moment. Moreover, the spin states of nitrogen-vacancy centers in diamonds undergoing full rotation were successfully controlled, allowing accurate angular trajectory reconstruction and demonstrating high rotational stability over extended periods. These achievements mark progress toward interfacing full rotation with internal magnetic degrees of freedom in micron-scale objects. In particular, it extends significantly the type of particles that can be rotated, such as ferromagnets, which offers direct implications for the study of large gyromagnetic effects at the micro-scale.

quant-ph↗

arXiv2022

Planar Magnetic Paul Traps for Ferromagnetic Particles

We present a study on the trapping of hard ferromagnetic particles using alternating magnetic fields, with a focus on planar trap geometries. First, we realize and characterize a magnetic Paul trap design for millimeter-size magnets based on a rotating magnetic potential. Employing a physically rotating platform with two pairs of permanent magnets with opposite poles, we show stable trapping of hard ferromagnets a centimeter above the trap and demonstrate that the particle shape plays a critical role in the trapping. Finally, we propose a chip trap design that will open a path to studies of gyromagnetic effects with ferromagnetic micro-particles.

quant-ph↗

arXiv2022

Spin-Controlled Quantum Interference of Levitated Nanorotors

We describe how to prepare an electrically levitated nanodiamond in a superposition of orientations via microwave driving of a single embedded nitrogen-vacancy (NV) center. Suitably aligning the magnetic field with the NV center can serve to reach the regime of ultrastrong coupling between the NV and the diamond rotation, enabling single-spin control of the particle's three-dimensional orientation. We derive the effective spin-oscillator Hamiltonian for small amplitude rotation about the equilibrium configuration and develop a protocol to create and observe quantum superpositions of the particle orientation. We discuss the impact of decoherence and argue that our proposal can be realistically implemented with near-future technology.

quant-ph↗

arXiv2022

Thermometry of an optically levitated nanodiamond

Using the spin properties of nitrogen-vacancy (NV) centers in levitated diamond, we characterize the absorption of single nanodiamonds. We first calibrate the thermometry response of the NV centers embedded in our nanodiamonds. Then, using this calibration, we estimate the absorption cross-section of single levitated nanodiamonds. We show that this absorption is extrinsic and dominated by volumic effects. Our work opens the way to diamond materials optimization for levitation quantum experiments. It also demonstrates optical levitation as a unique platform to characterize material thermal properties at the nanoparticle level.

quant-ph↗

arXiv2021

Spin-mechanics with nitrogen-vacancy centers and trapped particles

Controlling the motion of macroscopic oscillators in the quantum regime has been the subject of intense research in recent decades. In this direction, opto-mechanical systems, where the motion of micro-objects is strongly coupled with laser light radiation pressure, have had tremendous success. In particular, the motion of levitating objects can be manipulated at the quantum level thanks to their very high isolation from the environment under ultra-low vacuum conditions. To enter the quantum regime, schemes using single long-lived atomic spins, such as the electronic spin of nitrogen-vacancy (NV) centers in diamond, coupled with levitating mechanical oscillators have been proposed. At the single spin level, they offer the formidable prospect of transferring the spins' inherent quantum nature to the oscillators, with foreseeable far-reaching implications in quantum sensing and tests of quantum mechanics. Adding the spin degrees of freedom to the experimentalists' toolbox would enable access to a very rich playground at the crossroads between condensed matter and atomic physics. We review recent experimental work in the field of spin-mechanics that employ the interaction between trapped particles and electronic spins in the solid state and discuss the challenges ahead. Our focus is on the theoretical background close to the current experiments, as well as on the experimental limits, that, once overcome, will enable these systems to unleash their full potential.

quant-ph↗

arXiv2018

Quantum optical memory protocols in atomic ensembles

We review a series of quantum memory protocols designed to store the quantum information carried by light into atomic ensembles. In particular, we show how a simple semiclassical formalism allows to gain insight into various memory protocols and to highlight strong analogies between them. These analogies naturally lead to a classification of light storage protocols into two categories, namely photon echo and slow-light memories. We focus on the storage and retrieval dynamics as a key step to map the optical information into the atomic excitation. We finally review various criteria adapted for both continuous variables and photon-counting measurement techniques to certify the quantum nature of these memory protocols.

quant-ph↗

arXiv2017

Electron spin resonance from NV centers in diamonds levitating in an ion trap

We report observations of the Electron Spin Resonance (ESR) of Nitrogen Vacancy (NV) centers in diamonds that are levitating in an ion trap. Using a needle Paul trap operating under ambient conditions, we demonstrate efficient microwave driving of the electronic spin and show that the spin properties of deposited diamond particles measured by the ESR are retained in the Paul trap. We also exploit the ESR signal to monitor the rotation of levitating monocrystals, a first step towards spin-controlled mechanical systems in scattering-free traps.

quant-ph↗

arXiv2017

Stimulated Raman Adiabatic control of a nuclear spin in diamond

Coherent manipulation of nuclear spins is a highly desirable tool for both quantum metrology and quantum computation. However, most of the current techniques to control nuclear spins lack of being fast impairing their robustness against decoherence. Here, based on Stimulated Raman Adiabatic Passage, and its modification including shortcuts to adiabaticity, we present a fast protocol for the coherent manipulation of nuclear spins. Moreover, we show how to initialise a nuclear spin starting from a thermal state, and how to implement Raman control for performing Ramsey spectroscopy to measure the dynamical and geometric phases acquired by nuclear spins.

cond-mat.mes-hall↗

arXiv2015

Light-shift modulated photon-echo

We show that the AC-Stark shift (light-shift) is a powerful and versatile tool to control the emission of a photon-echo in the context of optical storage. As a proof-of-principle, we demonstrate that the photon-echo efficiency can be fully modulated by applying light-shift control pulses in an erbium doped solid. The control of the echo emission is attributed to the spatial gradient induced by the light-shift beam.

quant-ph↗

arXiv2015

Free space interference experiments with single photons and single ions

Trapped ion crystals have proved to be one of the most viable physical implementations of quantum registers and a promising candidate for a scalable realization of quantum networks. The latter will require the development of an efficient interface between trapped ions and photons. We describe two research directions that are currently investigated to realize such photonic quantum interfaces in free space using high numerical aperture optics. The first approach investigates how strong focusing of light onto a single ion can increase the interaction strength to achieve efficient interaction between a photon and the ion. The second approach uses a probabilistic measurement on scattered photons to generate entanglement between two ions that could be used to distribute information in a quantum network. For both approaches a higher numerical aperture would increase the efficiency of the interface.

quant-ph↗

arXiv2015

Spin Wave Diffraction Control and Read-out with a Quantum Memory for Light

A scheme for control and read-out of diffracted spins waves to propagating light fields is presented. Diffraction is obtained via sinusoidally varying lights shifts and ideal one-to-one mapping to light is realized using a gradient echo quantum memory. We also show that dynamical control of the diffracted spin waves spatial orders can be implemented to realize a quantum pulse sequencer for temporal modes that have high time-bandwidth products. Full numerical solutions suggest that both co-propagating and couterpropagating light shift geometries can be used, making the proposal applicable to hot and cold atomic vapours as well as solid state systems with two-level atoms.

quant-ph↗

arXiv2012

Quantum memory with a single two-level atom in a half cavity

We propose a setup for quantum memory based on a single two-level atom in a half cavity with a moving mirror. We show that various temporal shapes of incident photon can be efficiently stored and readout by shaping the time-dependent decay rate $γ(t)$ between the atom and the light. This is achieved uniquely by an appropriate motion of the mirror without the need for additional control laser or atomic level. We present an analytical expression for the efficiency of the process and study its dependence on the ratio between the incident light field bandwidth and the atomic decay rate. We discuss possible implementations and experimental issues, particularly for a single atom or ion in a half cavity quantum optical setup as well as a superconducting qubit in the context of circuit QED.

quant-ph↗