Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

The interaction of matter and light is one of the fundamental processes occurring in nature, and its most elementary form is realized when a single atom interacts with a single photon. Reaching this regime has been a major focus of research in atomic physics and quantum optics1 for several decades and has generated the field of cavity quantum electrodynamics2,3. Here we perform an experiment in which a superconducting two-level system, playing the role of an artificial atom, is coupled to an on-chip cavity consisting of a superconducting transmission line resonator. We show that the strong coupling regime can be attained in a solid-state system, and we experimentally observe the coherent interaction of a superconducting two-level system with a single microwave photon. The concept of circuit quantum electrodynamics opens many new possibilities for studying the strong interaction of light and matter. This system can also be exploited for quantum information processing and quantum communication and may lead to new approaches for single photon generation and detection.

https://arxiv.org/pdf/cond-mat/0407325.pdf

Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics

Majorana fermions are particles identical to their own antiparticles. They have been theoretically predicted to exist in topological superconductors. Here, we report electrical measurements on indium antimonide nanowires contacted with one normal (gold) and one superconducting (niobium titanium nitride) electrode. Gate voltages vary electron density and define a tunnel barrier between normal and superconducting contacts. In the presence of magnetic fields on the order of 100 millitesla, we observe bound, midgap states at zero bias voltage. These bound states remain fixed to zero bias, even when magnetic fields and gate voltages are changed over considerable ranges. Our observations support the hypothesis of Majorana fermions in nanowires coupled to superconductors.

Signatures of Majorana Fermions in Hybrid Superconductor-Semiconductor Nanowire Devices

Topological photonics is a rapidly emerging field of research in which geometrical and topological ideas are exploited to design and control the behavior of light. Drawing inspiration from the discovery of the quantum Hall effects and topological insulators in condensed matter, recent advances have shown how to engineer analogous effects also for photons, leading to remarkable phenomena such as the robust unidirectional propagation of light, which hold great promise for applications. Thanks to the flexibility and diversity of photonics systems, this field is also opening up new opportunities to realize exotic topological models and to probe and exploit topological effects in new ways. This article reviews experimental and theoretical developments in topological photonics across a wide range of experimental platforms, including photonic crystals, waveguides, metamaterials, cavities, optomechanics, silicon photonics, and circuit QED. A discussion of how changing the dimensionality and symmetries of photonics systems has allowed for the realization of different topological phases is offered, and progress in understanding the interplay of topology with non-Hermitian effects, such as dissipation, is reviewed. As an exciting perspective, topological photonics can be combined with optical nonlinearities, leading toward new collective phenomena and novel strongly correlated states of light, such as an analog of the fractional quantum Hall effect.

Topological Photonics

We demonstrated coherent control of a quantum two-level system based on two-electron spin states in a double quantum dot, allowing state preparation, coherent manipulation, and projective readout. These techniques are based on rapid electrical control of the exchange interaction. Separating and later recombining a singlet spin state provided a measurement of the spin dephasing time, T2*, of E10 nanoseconds, limited by hyperfine interactions with the gallium arsenide host nuclei. Rabi oscillations of two-electron spin states were demonstrated, and spin-echo pulse sequences were used to suppress hyperfine-induced dephasing. Using these quantum control techniques, a coherence time for two-electron spin states exceeding 1 microsecond was observed.

/pdf/coherent-manipulation-of-coupled-electron-spins-in-3azu0qfv16.pdf

Coherent manipulation of coupled electron spins in semiconductor quantum dots.

We have designed and operated a superconducting tunnel junction circuit that behaves as a two-level atom: the "quantronium." An arbitrary evolution of its quantum state can be programmed with a series of microwave pulses, and a projective measurement of the state can be performed by a pulsed readout subcircuit. The measured quality factor of quantum coherence Qphi approximately 25,000 is sufficiently high that a solid-state quantum processor based on this type of circuit can be envisioned.

/pdf/manipulating-the-quantum-state-of-an-electrical-circuit-573whw51uz.pdf

Manipulating the Quantum State of an Electrical Circuit

We have fabricated an array of ultrasmall tunnel junctions which acts like a turnstile for single electrons. When alternating voltage of frequency f is applied to a gate, one electron is transferred per cycle through the device. This results in a current plateau in the current-voltage characteristic at I=ef. The overall behavior of the device is well explained by the theory of Coulomb blockade of electron tunneling. We discuss the accuracy limitations of this device.

/pdf/frequency-locked-turnstile-device-for-single-electrons-5v8jyvo33d.pdf

Frequency-locked turnstile device for single electrons

We have designed and operated a device consisting of three nanoscale tunnel junctions biased below the Coulomb gap. Phase shifted r.f. voltages of frequency f applied to two gates "pump" one electron per cycle through the device. This is shown experimentally by plateaus in the current-voltage characteristic at I = ± ef, the sign of the current depending on the relative phase of the r.f. voltages and not on the sign of the bias voltage.

https://iopscience.iop.org/article/10.1209/0295-5075/17/3/011/pdf

Single-Electron Pump Based on Charging Effects

The current-voltage characteristic of an ultrasmall tunnel junction is calculated for arbitrary frequency dependence of the impedance presented to the junction by its electromagnetic environment. It is shown that the Coulomb blockade of tunneling is washed out by quantum fluctuations of the charge on the junction capacitor except for ultrahigh impedance environments. Two simple cases where the environment can be treated as an inductor or resistor are examined in detail. Effects of finite temperatures are discussed.

Effect of the electromagnetic environment on the Coulomb blockade in ultrasmall tunnel junctions.

We have measured with a tunnel probe the energy distribution function of Landau quasiparticles in metallic diffusive wires connected to two reservoir electrodes, with an applied bias voltage. The distribution function in the middle of a 1.5-mm-long wire resembles the half sum of the Fermi distributions of the reservoirs. The distribution functions in 5- mm-long wires are more rounded, due to interactions between quasiparticles during the longer diffusion time across the wire. From the scaling of the data with the bias voltage, we find that the scattering rate between two quasiparticles varies as « 22 , where « is the energy transferred. [S0031-9007(97)04367-6] The present understanding of metals is based on Landau’s theory of Fermi liquids. In this model, the elementary excitations of the fluid of interacting electrons are nearly independent fermionic quasiparticles [1]. In disordered metals, residual interactions between quasiparticles lead in mesoscopic samples to measurable corrections to the density of states, and limit the phase coherence of quasiparticles [2]. These effects have been widely investigated experimentally and theoretically in the last 20 years [3]. However, the most elementary manifestation of interactions, namely, the transfer of energy between quasiparticles, has been observed only at energies of order 1 eV by time-resolved spectroscopy of a metallic film following a laser pulse [4], and in the meV range through the establishment of an electron temperature in the so-called hotelectron regime [5]. Indications as to the speed at which this thermalization proceeds were obtained in recent shot noise experiments [6]. In this Letter, we report a direct measurement of the energy transfer rates between quasiparticles in diffusive metallic wires. We have measured the energy distribution function of quasiparticles in wires in a stationary out-ofequilibrium situation, at low enough temperature so that quasiparticle-quasiparticle interaction is the dominant inelastic process. The deviations of the energy distribution function from the Fermi distribution give access to the energy transfer rates. We force the wire out of equilibrium by placing it between two reservoir electrodes [7] biased at different potentials, 0 and U, as shown in Fig. 1. The local distribution function is probed with a superconducting electrode connected to the wire by a tunnel junction. The experiment exploits the property of the distribution function to have different shapes depending on the amount of inelastic collisions a quasiparticle experiences during its diffusion time through the wire. The steady-state distribution function fsx, Ed in a metallic wire of length L, which depends on the position X › xL measured from the right electrode, and on the energy E, results from the combined action of the elastic diffusion and of interactions. It obeys the Boltzmann

https://iramis.cea.fr/drecam/spec/Pres/Quantro/Qsite/publi/articles/fichiers/preprints/97-PRL-Pothier-relax.pdf

Hugues Pothier

Papers

Manipulating the Quantum State of an Electrical Circuit

Frequency-locked turnstile device for single electrons

Single-Electron Pump Based on Charging Effects

Effect of the electromagnetic environment on the Coulomb blockade in ultrasmall tunnel junctions.

Energy distribution function of quasiparticles in mesoscopic wires