Roadmap on structured light

Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized.Peer ReviewedPostprint (published version

Development of the novel transportable online mass-spectrometer PILOT-Trap with dynamic buffer-gas cooling for stored ions

The novel transportable PILOT-Trap experiment set up in the framework of this thesis aims to measure masses of short-lived nuclides with low production rates and half-lives > 100 ms with relative uncertainties of about 10-8. Applications for these precision mass measurements include atomic, nuclear and neutrino physics. The setup of the experiment includes a 6T superconducting coldhead-cooled magnet, which ensures transportability to different radioactive beam facilities. There, this setup enables mass measurements of, for example, heavy or superheavy nuclides that are produced only in tiny quantities of a few ions per hour. To deal with these low production rates a single trap is planned to be used for cooling the ion’s motions with a modified dynamic buffer-gas cooling technique as well as for measuring the ion’s motional frequencies. To make such a combination of two techniques in one trap feasible, a fast piezo valve is being developed, which enables a rapid and precisely timed helium injection into the Penning trap, followed by a fast helium release to be directly able to measure in the same trap. The latter is going to be realized by the developed rotating-disc approach. The cooling of the ion’s motions and the measurement of its motional frequencies in the same trap increases the overall efficiency by avoiding the ion transport stage between different traps. In addition to the development of the dynamic cooling method, the setup and initial test measurements of the PILOT-Trap mass spectrometer developed in this work are presented. These range from the initial detection of ions at the detector, through the storage and cooling of ions, to the performance of phase-sensitive measurements

Roadmap on structured light

Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized

Insights into the Allosteric Regulation and Exploitation of the MAPK Phosphatases as Therapeutic Targets

Protein tyrosine phosphatases (PTPs), while important regulatory enzymes, have proven a challenge to elucidate their mechanisms of actions, distinct functions, as well as their potential inhibition. These enzymes, responsible for the removal of phosphate groups from tyrosine residues, share high domain and sequence homology and a charged active site. Two factors that increase the difficulty in using small molecules, either as activators or inhibitors, to investigate their functions in cells. A subclass of the PTPs is the mitogen-activated protein kinases (MAPKs) phosphatases (MKPs), responsible for the dephosphorylation and inactivation of the three groups of MAPKs: ERK, p38 MAPK, and JNK. These kinases trigger major cell functions including apoptosis, migration, and differentiation as a response to external stimuli such as cellular stress and growth factors. Thus, aberrant signaling of proteins in the MAPK pathway, such as the MKPs, have been implicated in a host of diseases including cancer, diabetes, fibrosis, and autoimmune diseases. Several MAPK inhibitors have been successfully established while MKP inhibition has remained a challenge. The MKPs share high sequence and domain homology, a charged active site, and target the same three groups of MAPKs. All factors that often contribute to small molecules that have weak potency, poor cell permeability, and non-specificity for one MKP over the other. As such, small molecule regulation of the MKPs requires a combination of techniques and creativity in approach. One way to circumvent poor small molecule hits is to develop small molecule targets that attack/bind to the MKPs outside of their active site, i.e., allosteric inhibitors. My thesis focuses on current progress in the field of MKP small molecule inhibition, including a highly-selective small molecule inhibitor of one of the MKPs known as MKP5. Additionally, a co-crystal structure of MKP5 with this small molecule, revealed that the molecule bound to a site on MKP5 8 Å away from the active site, revealing a novel binding site. Interestingly, sequence alignment of the MKPs demonstrate that this binding site is somewhat conserved amongst the MKPs. Here, I delve into the importance of this novel region, particularly a key tyrosine residue within this site that is required for compound binding, and MKP5 functionality. Additionally, I explore this site in one of the closest family members to MKP5, MKP7, and compare the ways in which this pocket mediates both MKPs’ activity. The data presented here suggests that this tyrosine residue is critical for substrate recognition and inactivation in both MKP5 and MKP7. This new information on the tyrosine residue within the allosteric site, paired with the knowledge from our previously published work, that there are other residues within this pocket that can confer MKP inhibitor specificity, opens the door for development of selective inhibitors of the MKPs. Thus, this thesis provides a small piece to the puzzle of therapeutic targeting of the MKPs in many diseases

The development of microfabricated ion traps towards quantum information and simulation

Trapped ions within Paul traps have shown to be a promising architecture in the realisation of a quantum information processor together with the ability of providing quantum simulations. Linear Paul traps have demonstrated long coherence times with ions being well isolated from the environment, single and multi-qubit gates and the high fidelity detection of states. The scalability to large number of qubits, incorporating all the previous achievements requires an array of linear ion traps. Microfabrication techniques allow for fabrication and micron level accuracy of the trap electrode dimensions through photolithography techniques. The first part of this thesis presents the experiential setup and trapping of Yb+ ions needed to test large ion trap arrays. This include vacuum systems that can host advanced symmetric and asymmetric ion traps with up to 90 static voltage control electrodes. Demonstration of a single trapped Yb+ ion within a two-layer macroscopic ion trap is presented. with an ion-electrode distance of 310(10) μm. The anomalous heating rate and spectral noise density of the trap was measured, a main form of decoherence within ion traps. The second half of this thesis presents the design and fabrication of multi-layer asymmetric ion traps. This allows for isolated electrodes that cannot be accessed via surface pathways, allowing for higher density of electrodes as well as creating novel trap designs that allow for the potential of quantum simulations to be demonstrated. These include two-dimensional lattices and ring trap designs in which the isolated electrodes provide more control in the ion position. For the microfabrication of these traps I present a novel high-aspect ratio electroplated electrode design that provides shielding of the dielectric layer. This provides a means to mitigate stray electric field due to charge build up on the dielectric surfaces. Electrical testing of the trap structures was performed to test bulk breakdown and surface flashover of the ion trap architectures. Results showed sufficient isolation between electrodes for both radio frequency and static breakdown. Surface flashover voltage measurements over the dielectric layer showed an improvement of more than double over previous results using a new fabrication technique. This will allow for more powerful ion trap chips needed for the next generation of microfabricated ion trap arrays for scalable quantum technologies

Quantum Physics Exploring Gravity in the Outer Solar System: The Sagas Project

We summarise the scientific and technological aspects of the SAGAS (Search for Anomalous Gravitation using Atomic Sensors) project, submitted to ESA in June 2007 in response to the Cosmic Vision 2015-2025 call for proposals. The proposed mission aims at flying highly sensitive atomic sensors (optical clock, cold atom accelerometer, optical link) on a Solar System escape trajectory in the 2020 to 2030 time-frame. SAGAS has numerous science objectives in fundamental physics and Solar System science, for example numerous tests of general relativity and the exploration of the Kuiper belt. The combination of highly sensitive atomic sensors and of the laser link well adapted for large distances will allow measurements with unprecedented accuracy and on scales never reached before. We present the proposed mission in some detail, with particular emphasis on the science goals and associated measurements.Comment: 39 pages. Submitted in abridged version to Experimental Astronom

Single Ion Mass Spectrometry at 100 ppt and Beyond

Abstract. Using a Penning trap single ion mass spectrometer, our group has measured the atomic masses of 14 isotopes with a fractional accuracy of about 10 −10 . The masses were extracted from 28 cyclotron frequency ratios of two ions altenately confined in our trap. The precision on these measurements was limited by the temporal fluctuations of our magnetic field during the 5-10 minutes required to switch from one ion to the other. By trapping two different ions in the same Penning trap at the same time, we can now simultaneously measure their two cyclotron frequencies and extract the ratio with a precision of about 10 −11 in only a few hours. We have developed novel techniques to measure and control the motion of the two ions in the trap and we are currently using these tools to carefully investigate the important question of systematic errors in those measurements. Overview Accuracy in mass spectrometry has been advanced over two orders of magnitude by the use of resonance techniques to compare the cyclotron frequencies of single trapped ions. This paper provides an overview of the MIT Penning trap apparatus, techniques and measurements. We begin by describing the various interesting applications of our mass measurements and the wide-ranging impact they have on both fundamental physics and metrology. In the same section, we also describe further scientific applications that an improved accuracy would open. This serves as a motivation for our most current work (described in Sect. 4) to increase our precision by about an order of magnitude. Before describing the latest results, we give in Sect. 3 an overview of our apparatus and methods, with special emphasis on the techniques which we have developed for making measurements with accuracy around 10 −10 . In those measurements, we alternately trapped two different ions (one at the time) and compared their cyclotron frequencies to obtain their mass ratio. The main limitation of this method was the fact that our stable magnetic field would typically fluctuate by several parts in 10 10 during the 5-10 minutes required to switch from one ion to the other. In order to eliminate this problem, we now confine both ions simultaneously in our Penning trap. In Sect. 4, we describe the various techniques that have allowed us to load a pair in the trap and demonstrate a significant gain in precision from simultaneously measuring both their cyclotron frequencies. New tools to measure and control the motion of the ions are also presented. Those tools are invaluable in our current investigation of the important questio

Quantum Computing for Fusion Energy Science Applications

This is a review of recent research exploring and extending present-day quantum computing capabilities for fusion energy science applications. We begin with a brief tutorial on both ideal and open quantum dynamics, universal quantum computation, and quantum algorithms. Then, we explore the topic of using quantum computers to simulate both linear and nonlinear dynamics in greater detail. Because quantum computers can only efficiently perform linear operations on the quantum state, it is challenging to perform nonlinear operations that are generically required to describe the nonlinear differential equations of interest. In this work, we extend previous results on embedding nonlinear systems within linear systems by explicitly deriving the connection between the Koopman evolution operator, the Perron-Frobenius evolution operator, and the Koopman-von Neumann evolution (KvN) operator. We also explicitly derive the connection between the Koopman and Carleman approaches to embedding. Extension of the KvN framework to the complex-analytic setting relevant to Carleman embedding, and the proof that different choices of complex analytic reproducing kernel Hilbert spaces depend on the choice of Hilbert space metric are covered in the appendices. Finally, we conclude with a review of recent quantum hardware implementations of algorithms on present-day quantum hardware platforms that may one day be accelerated through Hamiltonian simulation. We discuss the simulation of toy models of wave-particle interactions through the simulation of quantum maps and of wave-wave interactions important in nonlinear plasma dynamics.Comment: 42 pages; 12 figures; invited paper at the 2021-2022 International Sherwood Fusion Theory Conferenc

Temas selectos en física cuántica de muchos cuerpos: sistemas cuánticos integrables y abiertos, el método variacional de la matriz densidad reducida y aislantes topológicos

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, leída el 07-06-2021The many-body problem is central and ubiquitous in quantum physics. Its applications are far reaching, varying from the design of new drugs to the research on novel nanotechnologies or building quantum computers. In this thesis we have studied three relevant topics of quantum many-bodyphysics: the description of new exactly solvable models that describe the evolution of quantum systems in contact with the environment, the advance in the variational reduced density matrix method to compute ground states of closed quantum systems and the characterization of the topological phases and currents in topological insulators...El problema de muchos cuerpos es un tema central y omnipresente en la física cuantica con aplicaciones muy variadas, desde el diseño de nuevos farmacos hasta la investigacion en nanotecnologías o la construccion de los ordenadores cuanticos. En esta tesis hemos estudiado tres temas relevantes en fsica cuantica de muchos cuerpos: la descripcion de nuevos modelos exactamente solubles que describen la interaccion de un sistema con su entorno, el avance en el metodo variacional de la matriz densidad reducida para calcula restados fundamentales de sistemas cuanticos cerrados y la caracterizacion de las fases y corrientes topologicas en aislantes topologicos...Fac. de Ciencias FísicasTRUEunpu

Orbiting Rainbows: Optical Manipulation of Aerosols and the Beginnings of Future Space Construction

Our objective is to investigate the conditions to manipulate and maintain the shape of an orbiting cloud of dust-like matter so that it can function as an ultra-lightweight surface with useful and adaptable electromagnetic characteristics, for instance, in the optical, RF, or microwave bands. Inspired by the light scattering and focusing properties of distributed optical assemblies in Nature, such as rainbows and aerosols, and by recent laboratory successes in optical trapping and manipulation, we propose a unique combination of space optics and autonomous robotic system technology, to enable a new vision of space system architecture with applications to ultra-lightweight space optics and, ultimately, in-situ space system fabrication. Typically, the cost of an optical system is driven by the size and mass of the primary aperture. The ideal system is a cloud of spatially disordered dust-like objects that can be optically manipulated: it is highly reconfigurable, fault-tolerant, and allows very large aperture sizes at low cost. See Figure 1 for a scenario of application of this concept. The solution that we propose is to construct an optical system in space in which the nonlinear optical properties of a cloud of micron-sized particles are shaped into a specific surface by light pressure, allowing it to form a very large and lightweight aperture of an optical system, hence reducing overall mass and cost. Other potential advantages offered by the cloud properties as optical system involve possible combination of properties (combined transmit/receive), variable focal length, combined refractive and reflective lens designs, and hyper-spectral imaging. A cloud of highly reflective particles of micron-size acting coherently in a specific electromagnetic band, just like an aerosol in suspension in the atmosphere, would reflect the Sun's light much like a rainbow. The only difference with an atmospheric or industrial aerosol is the absence of the supporting fluid medium. This new concept is based on recent understandings in the physics of optical manipulation of small particles in the laboratory and the engineering of distributed ensembles of spacecraft clouds to shape an orbiting cloud of micron-sized objects. In the same way that optical tweezers have revolutionized micro- and nano-manipulation of objects, our breakthrough concept will enable new large scale NASA mission applications and develop new technology in the areas of Astrophysical Imaging Systems and Remote Sensing because the cloud can operate as an adaptive optical imaging sensor. While achieving the feasibility of constructing one single aperture out of the cloud is the main topic of this work, it is clear that multiple orbiting aerosol lenses could also combine their power to synthesize a much larger aperture in space to enable challenging goals such as exoplanet detection. Furthermore, this effort could establish feasibility of key issues related to material properties, remote manipulation, and autonomy characteristics of cloud in orbit. There are several types of endeavors (science missions) that could be enabled by this type of approach, i.e. it can enable new astrophysical imaging systems, exoplanet search, large apertures allow for unprecedented high resolution to discern continents and important features of other planets, hyperspectral imaging, adaptive systems, spectroscopy imaging through limb, and stable optical systems from Lagrange-points. Future micro-miniaturization might hold promise of a further extension of our dust aperture concept to other more exciting smart dust concepts with other associated capabilities