# Professor Hinds

Faculty of Natural SciencesDepartment of Physics

Chair in Physics

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### Contact

+44 (0)20 7594 7901ed.hinds

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### Assistant

Miss Sanja Maricic +44 (0)20 7594 7742

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### Location

213Blackett LaboratorySouth Kensington Campus

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## Publications

Publication Type
Year
to

264 results found

Schofield RC, Boissier S, Clear C, Bogusz DP, Burdekin P, Nur S, Jin L, Ovvyan A, Koppens FHL, Toninelli C, Pernice WHP, Hinds EA, Major KD, McCutcheon DPS, Hoggarth RA, Clark ASet al., 2022, Continuous-Wave Characterisation of Photon Indistinguishability and Nanophotonic Coupling

We use continuous-wave excitation of a single molecule to measure the full temporal wavepacket indistinguishability of emitted photons, and show that continuous-wave light can determine the coupling of quantum emitters to arbitrary nanophotonic structures.

Conference paper

Schofield RC, Boissier S, Jin L, Ovvyan A, Nur S, Koppens FHL, Toninelli C, Pernice WHP, Major KD, Hinds EA, Clark ASet al., 2021, Coupling a Single Molecule to an Interrupted Nanophotonic Waveguide

Single organic molecules have recently seen increased interest for use as single photon sources [1]. They emit photons with high efficiency and at favourable wavelengths for coupling to other quantum systems. While the excitation of molecules and their subsequent radiative emission is efficient [2] , the generated photons can be difficult to efficiently collect. There is therefore a large amount of ongoing work on coupling organic molecules to nanophotonic structures to modify their emission. Evanescent coupling to nanophotonic [3] , [4] and hybrid plasmonic [5] waveguides has shown promise but has limitations; the molecules must be very close to the waveguide to be in the evanescent field of the guided mode which can cause the molecules to become unstable. Here I will present our recent work on coupling organic molecules to interrupted waveguides using on chip micro-capillaries [6].

Conference paper

Boissier S, Schofield R, Jin L, Ovvyan A, Nur S, Koppens FHL, Toninelli C, Pernice WHP, Major K, Hinds E, Clark Aet al., 2021, Coherent characterisation of a single molecule in a photonic black box, Nature Communications, Vol: 12, ISSN: 2041-1723

Extinction spectroscopy is a powerful tool for demonstrating the coupling of a single quantum emitter to a photonic structure. However, it can be challenging in all but the simplest of geometries to deduce an accurate value of the coupling eﬃciency from the measured spectrum. Here we develop a theoretical framework to deduce the coupling eﬃciency from the measured transmission and reﬂection spectra without precise knowledge of the photonic environment. We then consider the case of a waveguide interrupted by a transverse cut in which an emitter is placed. We apply that theory to a silicon nitride waveguide interrupted by a gap ﬁlled with anthracene that is doped with dibenzoterrylene molecules. We describe the fabrication of these devices, and experimentally characterise the waveguide coupling of a single molecule in the gap.

Journal article

Burdekin P, Grandi S, Newbold R, Hoggarth RA, Major KD, Hinds EA, Clark ASet al., 2021, Spectroscopy of Rubidium with a Tuneable Single Photon Source, Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), Publisher: IEEE

Conference paper

Schofield RC, Boissier S, Jin L, Ovvyan A, Nur S, Koppens FHL, Toninelli C, Pernice WHP, Major KD, Hinds EA, Clark ASet al., 2021, Adapted operating fault model for a heat pump life cycle's simulation by Petri net approach, Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), Publisher: IEEE

Conference paper

Burdekin P, Grandi S, Newbold R, Hoggarth RA, Major KD, Hinds EA, Clark ASet al., 2021, Spectroscopy of rubidium with a tuneable single photon source

Conference paper

Schofield RC, Boissier S, Jin L, Ovvyan A, Nur S, Koppens FHL, Toninelli C, Pernice WHP, Major KD, Hinds EA, Clark ASet al., 2021, Coupling a single molecule to an interrupted nanophotonic waveguide

Conference paper

Fitch NJ, Lim J, Hinds EA, Sauer BE, Tarbutt MRet al., 2021, Methods for measuring the electron's electric dipole moment using ultracold YbF molecules, QUANTUM SCIENCE AND TECHNOLOGY, Vol: 6, ISSN: 2058-9565

Journal article

Ho C, Devlin JA, Rabey I, Yzombard P, Lim J, Wright S, Fitch N, Hinds EA, Tarbutt MR, Sauer BEet al., 2020, New techniques for a measurement of the electron's electric dipole moment, New Journal of Physics, Vol: 22, ISSN: 1367-2630

The electric dipole moment of the electron (eEDM) can be measured with high precision using heavy polar molecules. In this paper, we report on a series of new techniques that have improved the statistical sensitivity of the YbF eEDM experiment. We increase the number of molecules participating in the experiment by an order of magnitude using a carefully designed optical pumping scheme. We also increase the detection efficiency of these molecules by another order of magnitude using an optical cycling scheme. In addition, we show how to destabilise dark states and reduce backgrounds that otherwise limit the efficiency of these techniques. Together, these improvements allow us to demonstrate a statistical sensitivity of 1.8 x 10⁻²⁸ e cm after one day of measurement, which is 1.2 times the shot-noise limit. The techniques presented here are applicable to other high-precision measurements using molecules.

Journal article

Grandi S, Nielsen MP, Cambiasso J, Boissier S, Major K, Reardon C, Krauss TF, Oulton R, Hinds E, Clark Aet al., 2019, Hybrid plasmonic waveguide coupling of photons from a single molecule, APL Photonics, Vol: 4, Pages: 086101-1-086101-6, ISSN: 2378-0967

We demonstrate the emission of photons from a single molecule into a hybrid gap plasmon waveguide (HGPW). Crystals of anthracene, doped with dibenzoterrylene (DBT), are grown on top of the waveguides. We investigate a single DBT molecule coupled to the plasmonic region of one of the guides, and determine its in-plane orientation, excited state lifetime and saturation intensity. The molecule emits light into the guide, which is remotely out-coupled by a grating. The second-order autocorrelation and cross-correlation functions show that the emitter is a single molecule and that the light emerging from the grating comes from that molecule. The couplinge fficiency is found to be βWG = 11.6(1:5)%. This type of structure is promising for building new functionality into quantum-photonic circuits, where localised regions of strong emitter-guide coupling can be interconnected by low-loss dielectric guides.

Journal article

Sabulsky DO, Dutta I, Hinds EA, Elder B, Burrage C, Copeland EJet al., 2019, Experiment to detect dark energy forces using atom interferometry, Physical Review Letters, Vol: 123, ISSN: 0031-9007

The accelerated expansion of the universe motivates a wide class of scalar field theories that modify general relativity (GR) on large scales. Such theories require a screening mechanism to suppress the new force in regions where the weak field limit of GR has been experimentally tested. We have used atom interferometry to measure the acceleration of an atom toward a macroscopic test mass inside a high vacuum chamber, where new forces can be unscreened. Our measurement shows no evidence of new forces, a result that places stringent bounds on chameleon and symmetron theories of modified gravity.

Journal article

Caldwell L, Devlin J, Williams H, Fitch N, Hinds E, Sauer B, Tarbutt Met al., 2019, Deep Laser Cooling and Efficient Magnetic Compression of Molecules, Physical Review Letters, Vol: 123, ISSN: 0031-9007

We introduce a scheme for deep laser cooling of molecules based on robust dark states at zero velocity. By simulating this scheme, we show it to be a widely applicable method that can reach the recoil limit or below. We demonstrate and characterise the method experimentally, reachinga temperature of 5.4(7) μK. We solve a general problem of measuring low temperatures for large clouds by rotating the phase-space distribution and then directly imaging the complete velocity distribution. Using the same phase-space rotation method, we rapidly compress the cloud. Applying the cooling method a second time, we compress both the position and velocity distributions.

Journal article

Grandi S, Nielsen MP, Cambiasso J, Boissier S, Major KD, Reardon C, Krauss TF, Oulton RF, Hinds EA, Clark ASet al., 2019, Hybrid plasmonic waveguide coupling of photons from a single molecule

We demonstrate the emission of photons from a single molecule into a hybridgap plasmon waveguide (HGPW). Crystals of anthracene, doped withdibenzoterrylene (DBT), are grown on top of the waveguides. We investigate asingle DBT molecule coupled to the plasmonic region of one of the guides, anddetermine its in-plane orientation, excited state lifetime and saturationintensity. The molecule emits light into the guide, which is remotelyout-coupled by a grating. The second-order auto-correlation andcross-correlation functions show that the emitter is a single molecule and thatthe light emerging from the grating comes from that molecule. The couplingefficiency is found to be $\beta_{WG}=11.6(1.5)\%$. This type of structure ispromising for building new functionality into quantum-photonic circuits, wherelocalised regions of strong emitter-guide coupling can be interconnected bylow-loss dielectric guides.

Working paper

, 2019, Novel method of sub-wavelength thin film growth for single photon emission from dye molecules

Conference paper

Boissier S, Schofield R, Major K, Grandi S, Boissier S, Hinds E, Clark Aet al., 2018, Efficient excitation of dye molecules for single photon generation, Journal of Physics Communications, Vol: 2, ISSN: 2399-6528

A reliable photon source is required for many aspects of quantum technology. Organic molecules are attractive for this application because they can have high quantum yield and can be photostable, even at room temperature. To generate a photon with high probability, a laser must excite the molecule efficiently. We develop a simple model for that efficiency and discuss how to optimise it. We demonstrate the validity of our model through experiments on a single dibenzoterrylene (DBT) molecule in an anthracene crystal. We show that the excitation probability cannot exceed 75% at room temperature, but can increase to over 99% if the sample is cooled to liquid nitrogen temperature. The possibility of high photon generation efficiency with only modest cooling is a significant step towards a reliable photon source that is simple and practical.

Journal article

Williams HJ, Caldwell L, Fitch NJ, Truppe S, Rodewald J, Hinds EA, Sauer BE, Tarbutt MRet al., 2018, Magnetic trapping and coherent control of laser-cooled molecules, Physical Review Letters, Vol: 120, ISSN: 0031-9007

We demonstrate coherent microwave control of the rotational, hyperfine and Zeeman states of ultracold CaF molecules, and the magnetic trapping of these molecules in a single, selectable quantum state. We trap about 5 X 10³ molecules for almost 2s at a temperature of 70(8) μK and a density of 1.2 X 10⁵ cm⁻³. We measure the state-specific loss rate due to collisions with background helium.

Journal article

Lim J, Almond J, Trigatzis M, Devlin J, Fitch N, Sauer B, Tarbutt M, Hinds Eet al., 2018, Laser cooled YbF molecules for measuring the electron's electric dipole moment, Physical Review Letters, Vol: 120, ISSN: 0031-9007

We demonstrate one-dimensional sub-Doppler laser cooling of a beam of YbF molecules to 100 μK. This is a key step towards a measurement of the electron's electric dipole moment using ultracold molecules. We compare the effectiveness of magnetically-assisted and polarization-gradient sub-Doppler cooling mechanisms. We model the experiment and fi nd good agreement with our data.

Journal article

Truppe S, Williams HJ, Hambach M, Caldwell L, Fitch NJ, Hinds EA, Sauer BE, Tarbutt MRet al., 2017, Molecules cooled below the Doppler limit, Nature Physics, Vol: 13, Pages: 1173-1176, ISSN: 1745-2473

The ability to cool atoms below the Doppler limit -- the minimum temperaturereachable by Doppler cooling -- has been essential to most experiments withquantum degenerate gases, optical lattices and atomic fountains, among manyother applications. A broad set of new applications await ultracold molecules,and the extension of laser cooling to molecules has begun. A molecularmagneto-optical trap has been demonstrated, where molecules approached theDoppler limit. However, the sub-Doppler temperatures required for mostapplications have not yet been reached. Here we cool molecules to 50 uK, wellbelow the Doppler limit, using a three-dimensional optical molasses. Theseultracold molecules could be loaded into optical tweezers to trap arbitraryarrays for quantum simulation, launched into a molecular fountain for testingfundamental physics, and used to study ultracold collisions and ultracoldchemistry.

Journal article

Williams H, Truppe S, Hambach M, Caldwell L, Fitch N, Hinds E, Sauer B, Tarbutt Met al., 2017, Characteristics of a magneto-optical trap of molecules, New Journal of Physics, Vol: 19, ISSN: 1367-2630

We present the properties of a magneto-optical trap (MOT) of CaFmolecules. We study the process of loading the MOT from a decelerated bu er-gas-cooled beam, and how best to slow this molecular beam in order to capture the most molecules. We determine how the number of molecules, the photon scattering rate, the oscillation frequency, damping constant, temperature, cloud size and lifetime depend on the key parameters of the MOT, especially the intensity and detuning of the main cooling laser. We compare our results to analytical and numerical models, to the properties of standard atomic MOTs, and to MOTs of SrF molecules. We load up to 2 x 10⁴ molecules, and measure a maximum scattering rate of 2.5 x 10⁶ s⁻¹ per molecule, a maximum oscillation frequency of 100 Hz, a maximum damping constant of 500 s⁻¹, and a minimum MOT rms radius of 1.5 mm. A minimum temperature of 730 μK is obtained by ramping down the laser intensity to low values. The lifetime, typically about 100 ms, is consistent with a leak out of the cooling cycle with a branching ratio of about 6 x 10⁻⁶. The MOT has a capture velocity of about 11 m/s.

Journal article

Truppe S, Hambach M, Skoff S, Bulleid N, Bumby J, Hendricks RJ, Hinds EA, Sauer BE, Tarbutt MRet al., 2017, A buffer gas beam source for short, intense and slow molecular pulses, Journal of Modern Optics, Vol: 65, Pages: 246-254, ISSN: 0950-0340

Experiments with cold molecules usually begin with a molecular source. We describe the construction and characteristics of a cryogenic buff er gas source of CaF molecules. The source emits pulses with a typical duration of 240 μs, a mean speed of about 150 m/s, and a flux of 5x 10¹⁰ molecules per steradian per pulse in a single rotational state.

Journal article

Truppe S, Williams HJ, Fitch NJ, Hambach M, Wall TE, Hinds EA, Sauer BE, Tarbutt MRet al., 2017, An intense, cold, velocity-controlled molecular beam by frequency-chirped laser slowing, NEW JOURNAL OF PHYSICS, Vol: 19, ISSN: 1367-2630

Using frequency-chirped radiation pressure slowing, we precisely control the velocity of a pulsed CaF molecular beam down to a few m s–1, compressing its velocity spread by a factor of 10 while retaining high intensity: at a velocity of 15 m s–1 the flux, measured 1.3 m from the source, is 7 × 105 molecules per cm2 per shot in a single rovibrational state. The beam is suitable for loading a magneto-optical trap or, when combined with transverse laser cooling, improving the precision of spectroscopic measurements that test fundamental physics. We compare the frequency-chirped slowing method with the more commonly used frequency-broadened slowing method.

Journal article

Lien Y-H, Barontini G, Scheucher M, Mergenthaler M, Goldwin J, Hinds EAet al., 2016, Observing coherence effects in an overdamped quantum system, Nature Communications, Vol: 7, ISSN: 2041-1723

It is usually considered that the spectrum of an optical cavity coupled to an atomic medium does not exhibit a normal-mode splitting unless the system satisfies the strong coupling condition, meaning the Rabi frequency of the coherent coupling exceeds the decay rates of atom and cavity excitations. Here we show that this need not be the case, but depends on the way in which the coupled system is probed. Measurements of the reflection of a probe laser from the input mirror of an overdamped cavity reveal an avoided crossing in the spectrum that is not observed when driving the atoms directly and measuring the Purcell-enhanced cavity emission. We understand these observations by noting a formal correspondence with electromagnetically induced transparency of a three-level atom in free space, where our cavity acts as the absorbing medium and the coupled atoms play the role of the control field.

Journal article

Grandi S, Major KD, Polisseni C, Boissier S, Clark AS, Hinds EAet al., 2016, Quantum dynamics of a driven two-level molecule with variable dephasing, Physical Review A, Vol: 94, ISSN: 1094-1622

The longitudinal (1) and transverse (2) decay rates of a two-level quantum system have a profound influenceon its evolution. Atomic systems with 2 = 121 have been studied extensively, but with the rise of solid-statequantum devices it is also important to consider the effect of stronger transverse relaxation due to interactionswith the solid environment. Here we study the quantum dynamics of a single organic dye molecule driven by alaser. We measure the variation of 2 with temperature and determine the activation energy for thermal dephasingof the optical dipole. Then we measure the second-order correlation function g(2)(τ ) of the light emitted by themolecule for various ratios 2/1 and saturation parameters S. We show that the general solution to the opticalBloch equations accurately describes the observed quantum dynamics over a wide range of these parameters,and we discuss the limitations of the various approximate expressions for g(2)(τ ) that appear in the literature.DOI:

Journal article

Rabey IM, Devlin JA, Hinds EA, Sauer BEet al., 2016, Low magnetic Johnson noise electric field plates for precision measurement, Review of Scientific Instruments, Vol: 87, ISSN: 1089-7623

We describe a parallel pair of high voltage electric field plates designed and constructed to minimise magnetic Johnson noise. They are formed by laminating glass substrates with commercially available polyimide (Kapton) tape, covered with a thin gold film. Tested in vacuum, the outgassing rate is less than 5 x 10 exp(-5) mbar.l/s. The plates have been operated at electric fields up to 8.3 kV/cm, when the leakage current is at most a few hundred pA. The design is discussed in the context of a molecular spin precession experiment to measure the permanent electric dipole moment of the electron.

Journal article

Polisseni C, Major KD, Boissier S, Grandi S, Clark AS, Hinds EAet al., 2016, Coupling dye molecules to a silicon nitride waveguide, Australian Conference on Optical Fibre Technology (ACOFT)

© OSA 2016. A dibenzoterrylene (DBT) molecule can emit single-photons into a waveguide. We have grown and characterised thin, DBT-doped anthracene crystals on photonic structures, including a silicon nitride ridge waveguide from which we detect single-photons.

Conference paper

Guttridge A, Hopkins SA, Kemp SL, Boddy D, Freytag R, Jones MPA, Tarbutt MR, Hinds EA, Cornish SLet al., 2016, Direct loading of a large Yb MOT on the S-1(0) -> P-3(1) transition, JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS, Vol: 49, ISSN: 0953-4075

Journal article

Cotter JP, McGilligan JP, Griffin PF, Rabey IM, Docherty K, Riis E, Arnold AS, Hinds EAet al., 2016, Design and fabrication of diffractive atom chips for laser cooling and trapping, Applied Physics B, Vol: 122, ISSN: 0946-2171

It has recently been shown that optical reflection gratings fabricated directly into an atom chip provide a simple and effective way to trap and cool substantial clouds of atoms (Nshii et al. in Nat Nanotechnol 8:321–324, 2013; McGilligan et al. in Opt Express 23(7):8948–8959, 2015). In this article, we describe how the gratings are designed and microfabricated and we characterise their optical properties, which determine their effectiveness as a cold atom source. We use simple scalar diffraction theory to understand how the morphology of the gratings determines the power in the diffracted beams.

Journal article

Hopkins SA, Butler K, Guttridge A, Kemp S, Freytag R, Hinds EA, Tarbutt MR, Cornish SLet al., 2016, A versatile dual-species Zeeman slower for caesium and ytterbium (vol 87, 043109, 2016), Review of Scientific Instruments, Vol: 87, ISSN: 1089-7623

Journal article

Hopkins SA, Butler K, Guttridge A, Kemp S, Cornish SL, Freytag R, Hinds EA, Tarbutt MRet al., 2016, A versatile dual-species Zeeman slower for caesium and ytterbium, Review of Scientific Instruments, Vol: 87, ISSN: 1089-7623

We describe the design, construction, and operation of a versatile dual-species Zeeman slower for both Cs and Yb, which is easily adaptable for use with other alkali metals and alkaline earths. With the aid of analytic models and numerical simulation of decelerator action, we highlight several real-world problems affecting the performance of a slower and discuss effective solutions. To capture Yb into a magneto-optical trap(MOT), we use the broad ¹S0 to ¹P1 transition at 399 nm for the slower and the narrow ¹S0 to ³P1 intercombination line at 556 nm for the MOT. The Cs MOT and slower both use the D2 line (6²S1/2 to 6²P3/2 at 852 nm. The slower can be switched between loading Yb or Cs in under 0.1 s. We demonstrate that within a few seconds the Zeeman slower loads more than 10⁹ Yb atoms and 10⁸ Cs atoms into their respective MOTs. These are ideal starting numbers for further experiments on ultracold mixtures and molecules.

Journal article

Polisseni C, Major K, Boissier S, Grandi S, Clark A, Hinds EAet al., 2016, A stable, single-photon emitter in a thin organic crystal for application to quantum-photonic devices, Optics Express, ISSN: 1094-4087

Journal article

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