| 20 gennaio
Partecipazione INRIM al confronto 'Supplementary Comparison EURAMET.EM-S32'
"Comparison of resistance standards at 1 TΩ and 100 TΩ":
sistemi di misura INRIM, analisi dei dati e interazioni con il Laboratorio pilota
Nel 2009 l'INRIM ha partecipato al confronto di misura EURAMET.EM-S32 di elevatissime
resistenze a livello 1 TΩ e 100 TΩ a cui hanno partecipato 18 Istituti Metrologici Europei.
Vengono descritti i sistemi ed incertezze di misura INRIM, l'analisi dei risultati
per il trattamento di dati provenienti da più campioni di pari valor nominale.
Viene sintetizzata l'interazione tra l'INRIM ed il METAS per la definizione dell'esito definitivo del confronto.
Flavio Galliana e Pier Paolo Capra
| 22 gennaio
Cold atoms experiments at University of São Paulo:
from quantum turbulence to compact atomic clocks
We shall discuss the experiments and results using cold atoms to
prepare BEC, to investigate quantum turbulence and to produce atomic
clocks. In special, the compact clock, using an expanding cloud of
cold atoms will be discussed.
Vanderlei Salvador Bagnato
Instituto de Física de São Carlos
Universidade de São Paulo
| 3 febbraio
Photonic States Manipulation in Atomic Ensembles
Quantum information processing requires efficient encoding, manipulation
and storage of quantum states.
Photons are excellent carriers of quantum information, since they travel
fast without being affected by external disturbances. On the other hand,
cold atomic ensembles are a very versatile tool to store, manipulate and
retrieve quantum states of light. In the past decade, they have been
extensively used to store and retrieve photonic states by using either
the so called Electromagnetically Induced Transparency (EIT) protocol,
or the DLCZ protocol, where the detection of a Raman photon triggers the
creation of a collective atomic excitation in a lambda-medium. The shared
excitation can be reconverted later into a single photon leaving the ensemble.
The process has been extensively investigated in the photon counting regime
showing the non-classical character of the emerging photonic state.
Only very recently the photonic states leaving the atomic ensemble have been
characterized by quantum homodyne tomography. The state is hence completely
described in the continuous variables picture by the reconstructed Wigner
function giving complete information on a welldefined spatial-temporal mode.
Atomic ensembles can be also used for manipulating photonic states by atomic
interactions and they are promising candidates to reach strong-nonlinearities
at the single-photon level. Photonic states can be converted into strongly
interacting particles, like collective excitations involving Rydberg atoms.
Interactions between Rydbergs in fact lead to a "blockade" phenomenon, where
each Rydberg atom blocks the excitation of its neighbors, which can result
in strong nonlinearities.
Laboratoire Kastler Brossel
Université Pierre et Marie Curie, Ecole Normale Supérieure, CNRS, Paris
| 12 febbraio
Including disorder in micromagnetic simulations: the road to imperfection
In this seminar you will see how material imperfections can be included in
micromagnetic simulations. Understanding domain wall motion in magnetic
nanowires is of paramount importance for the development of future spintronics
devices and simulations are a powerful tool to investigate this motion. However,
more often than not the effects of material imperfections are not taken into
account in these simulations.
A method will be shown to characterize simulated defects and its application
to find 2 possible implementations that give rise to defects with properties
that correspond to experimental values. The effects of this disorder on current
driven vortex domain wall motion will illustrate why disorder should be taken
into account. Furthermore, as there is a suspected link between the experimentally
measured disorder and the grains in material samples. A computationally efficient
way of simulating polycrystalline materials using voronoi cells will also be presented.
University of Ghent
| 12 febbraio
Astroparticle physics in space
Università di Trento
Dipartimento di Fisica
| 19 febbraio
Optical Lattice Clocks and Applications
Research on optical frequency standards based on cold atoms or ions has shown a great
advance in the last few years.
Among others, alkaline-earth atoms trapped in an optical lattice have demonstrated
Recently a strontium lattice clock demonstrated an uncertainty of 6e-18, the best in
frequency standards up to date.
The stability and accuracy of optical frequency standards will benefit many applications
and innovations, such as realization and dissemination of units in the Système International
(SI), quantum simulations, relativistic geodesy, test of fundamental constants variation and
tests of fundamental physics.
In the talk I will describe the development of an optical lattice clock based on ytterbium
atoms and the perspective for the near future.
Comparison with other clocks is planned, both local and remote, that will allow a
proof-of-principle relativistic geodesy experiment.
In addition, remote comparison with a quantum degenerate ytterbium gas experiment developed
in Florence will be useful for studies of collisional physics and quantum simulations.
| 26 febbraio
Un'infrastruttura in fibra ottica per la disseminazione di frequenza a 5e-19 su scala nazionale ed europea
A fiber optical link for frequency dissemination at 5e-19 on a European scale
Currently, time and frequency dissemination is performed with satellite microwave links. These techniques strongly limit
the comparison of remote primary frequency standards, and are completely inadequate for the comparison of optical clocks.
In recent years, an alternative method based on optical fiber has been developed, which improves the resolution by 5 orders
of magnitude. This is not only beneficial in time and frequency metrology, but paves the way for new opportunities in
fundamental physics, geodesy and radioastronomy as well.
INRIM has developed a 642 km optical link with the European Laboratory for Non Linear Spectroscopy (LENS) in Firenze.
This backbone has enabled absolute spectroscopic measurements between the two laboratories and will be upgraded to connect
other research centres in Italy ( Medicina (Bologna) Radio-telescopes, National Institute of Optics in Firenze,
National Council of Research in Milano) and in Europe. I will describe the optical link, the fiber-based remote comparison
of atomic clocks, and the future applications.
| 27 marzo
Comparison of non-classicality and Decoherence between photon added and photon subtracted squeezed coherent state
Non-classicality in a state of light is a valuable resource for quantum information processing.
Non-classicality is manifested by certain criteria such as sub-Poissonian distribution of photon numbers,
oscillation in the photon number distribution and negativity of the Wigner function.
Employing the technique of Integration within an Ordered Product (IWOP), I have calculated and compared
the non-classicality of photon added and photon subtracted squeezed coherent states. I have found that
photon addition generates more non-classicality in a squeezed coherent state than photon subtraction.
Decoherence of such states in amplitude and phase damping channel has also been analysed in this work.
How the photon number distribution will change under the influence of Decoherence will also be discussed.
| 11 aprile
Dai vulcani siciliani ai villaggi neolitici piemontesi.
Il viaggio dell'ossidiana attraverso lo studio delle sue proprietà magnetiche
In questo lavoro, si à posta attenzione ad alcuni parametri sperimentali per distinguere le diverse
distribuzioni e dimensioni dei granuli magnetici (ossidi di ferro: magnetite, titano-magnetite) nei principali
giacimenti di ossidiana del Mediterraneo. La potenzialità del metodo per tracciare la provenienza di
manufatti in ossidiana di interesse archeologico è stata valutata confrontando campioni geologici di
cinque isole (Lipari, Monte Arci – Sardegna, Palmarola, Pantelleria, Melos) con i campioni costitutivi di
una collezione di lamelle provenienti dal sito neolitico di Castello d'Annone, in provincia di Asti (22 campioni).
Sono state misurate: la suscettività magnetica iniziale x, la suscettività anisteretica xa e
la magnetizzazione rimanente (IRM) a T = 293 K (IRM293) e 77 K (IRM77). Sono state inoltre analizzate
le forme dei cicli di isteresi, sia a T = 293 K sia a T = 77 K. Lo studio dei parametri magnetici ricavabili
da queste misure permette una stima della distribuzione dei granuli ferrosi presenti nell'ossidiana,
distinguendone il contenuto in superparamagnetici (SP), singolo dominio (SD), pseudo singolo dominio (PSD)
e multidominio (MD). L'indicazione di provenienza ricavata dalle misure conferma le ipotesi già avanzate
dagli studi archeologici nell'Italia nord-occidentale sull'esistenza nel Neolitico di una via di commercio con
Lipari e la Sicilia, oltre a quella con la Sardegna, consolidata e favorita dalla vicinanza.
Università di Torino
| 14 aprile
Control of Quantum Sensors
The success of quantum-enhanced sensors relies on precise control of the experimental systems to
protect them from undesired sources of noise. Unfortunately, simple application of known strategies
to reduce decoherence does not necessarily translate into an improvement of phase measurements:
techniques such as dynamical decoupling that eliminate decoherence also eliminate the very signal
that one wishes to measure.
In this talk I will show how to extend control techniques to quantum metrology tasks, achieving a
better and more flexible compromise between sensitivity and noise protection. In addition,
tailoring the sensor dynamic can help reveal temporal and spatial information about the target.
We can for example use coherent control of quantum sensors to simultaneously reconstruct the
arbitrary profile of timevarying fields and correct for unwanted noise sources; or we can
achieve high frequency resolution, thus allowing precise spectroscopy.
I will illustrate applications of these strategies in experimental implementations based
on the NitrogenVacancy center in diamond.
Nuclear Science and Engineering Department
Massachusetts Institute of Technology
| 15 aprile
Atomic Frequency Standards in Brazil - Research and ongoing applications
In the recent years, using atomic transitions have become more and more frequent
in the definition of reference standards. The measurement capability reached by microwave
and optical frequency standards plays a fundamental role on these definitions.
Our research group has been establishing experiments in some of the several kinds of
atomic standards, and the goal of this presentation is to present the state of the art
in our laboratories. The results concern the 133Cs atomic fountain, the 133Cs compact
clock, the experiment with 88Sr, the structure under development for time and frequency
scientific metrology and applications in course for the use of such accurate and stable references.
Daniel Varela Magalhaes
São Carlos School of Engineering
University of São Paulo, Brazil
| 11 giugno
Superconducting nanowires for single-photon detection
Superconducting nanowire single photon detectors (SNSPDs) is an emergent technology which is rapidly
achieving unprecedented performances: single photon sensitivity in the 0.5–3.0 micron range with
detection efficiency above 90%, dark count rate below 1 kHz, dead time of a few nanoseconds, and
timing jitter as low as 20 ps. Photon number resolving is also possible and very recently counting
capability up to 12 photons has been demonstrated. These characteristics are attractive for quantum
technologies and high sensitivity long-distance communications, as well as for atmospheric remote
sensing and biological/medical sensing of ultra weak photon sources. As is often the case in applied
nanotechnology, it is a challenge to make devices that match with the macroscopic dimensions of the
available light sources (laser spots, etc). Both the fast temporal response and the device sensitivity
is generally degraded when the SNSPD active area is increased.
Here, a general overview of SNSPD will be given and our recent results will be presented on novel SNSPD
configurations for scaling up to macroscopic dimensions without losing the performance of the active
elements, thus enabling practical use of this nanotechnology. Presently NbN is the material of choice
for SNSPD. Results on alternative materials (WSi, YBCO) will be also presented.
Istituto Superconduttori, Materiali innovativi e dispositivi (SPIN) del CNR, Pozzuoli (Napoli)
| 11 giugno
Acustica subacquea: stato delle conoscenze e prospettive applicative
L'esplorazione dell'ambiente marino, in primo luogo di quello profondo, rappresenta una delle ultime grandi sfide.
L'ostilità di questo ambiente all'uomo e l'impossibilità di ricorrere alle onde elettromagnetiche
impongono l'uso della propagazione acustica. Nei suoi cento anni di storia l'acustica subacquea si è sviluppata
a partire dall'esigenza di essere di ausilio alla navigazione oceanica, ricevendo un enorme impulso nel periodo
bellico e post-bellico con la lotta antisommergibili, fino ad interessare al giorno d'oggi quasi ogni ambito
applicativo delle scienze e tecnologie marine.
Il seminario presenta alcuni casi di studio tra i più significativi con una descrizione dello stato dell'arte e
delle attuali prospettive di sviluppo, con particolare attenzione al tema della metrologia.
Istituto di Acustica e Sensoristica "O. M. Corbino" del CNR
| 15 luglio
Opto-Electronic Properties of Bismuth Oxide Thin Films and Applications
Bismuth oxide Bi2O3 has interesting technological applications, which have not been largely explored due to the
particular polymorphism of the material. Among the interesting properties, it is worth mentioning a large energy
gap (from 2 to 3.96 eV depending on the phase), high refractive index, dielectric permittivity, noticeable
photoconductivity and photoluminescence. Moreover, one of its phases presents the highest ionic conductivity.
Bismuth Oxide has five polymorphic forms: α, β, γ, δ and ω-Bi2O3.
Among them, the low-temperature α and the high-temperature γ phases are stable and the others are metastable.
The face-centered cubic δ-Bi2O3 is stable over a narrow range 729–825oC (melting point) and it is
the high ionic conductivity phase. Remarkably, it has been proved that the deposition of nanocrystalline thin films
allows the stabilization of the high temperature phase (δ) at room temperature. In order to study deeply the
properties and therefore possible applications of Bismuth oxide thin films for the energy and environmental areas,
Bismuth oxide thin films were deposited by reactive magnetron sputtering from a Bi2O3 target (99.95 at%) using radio
frequency and an Ar/O2 atmosphere (80/20). The films were deposited on silicon and glass substrates as a function of
the power (PW: 100-200 W) and the substrate temperature (Ts: 125-250oC). The films were characterized in
terms of the structural identification by X-ray diffraction (XRD) and Raman spectroscopy, the elemental composition
by X-ray photoelectron spectroscopy, the optical properties were determined by spectroscopy ellipsometry and the
electrical resistivity by analyzing the current-voltage curves measured using two-concentrically circular Pt electrodes
deposited on the surface.
The results indicated that stoichiometric Bi2O3 films were obtained but according to the Ts and PW, the crystalline
structure changed from the delta-phase, at the lowest energetic conditions, to beta and alpha as the substrate temperature
or power increased. Micro Raman showed that under energetic conditions, the films were not spatially uniform; presenting
phase differences (α and β). The electrical measurements of the as-deposited films (on glass) showed
the response of a highly electrical resistance material.
In this presentation, the evaluations of the Bismuth oxide thin films for two possible energetic and environmental
applications are presented. Firstly, we explore the photocatalytic response of the films studying the degradation of color
dyes (methyl orange) under different conditions of illumination, agitation and pH. The preliminary results indicated
a response comparable to the well-known TiO2 photocatalytic material. Secondly, the δ-phase films were stabilized up to
500oC by the addition of Ta ions opening the possibility of using them as the electrolyte layer for micro
solid oxide fuel cells.
Acknowledgements: This research received funding from the European Community Seven Framework Programme
(FP7-NMP-2010-EU-MEXICO) and CONACYT under grant agreements n. 263878 and 125141, respectively.
Sandra E. Rodil
Universidad Nacional Autónoma de México
| 21 luglio
Nanoscienza e nanotecnologia al NEST
Nanotechnology is moving fast towards becoming a trillion dollar market, as predicted
by the National Science Foundation back in 2000 for year 2015. This large figure is the
result of the pervasive impact of nanotechnology in many different fields notably nanomaterials,
but above all in the pharmaceutical and biomedical sectors.
In this talk I shall present some of the recent activities at NEST, the National Enterprise
for nanoScience and nanoTechnology both in the context of nanostructured materials and devices
for ICT and in the biomedical sectors. I shall also discuss the role of standardization and
certification of nanoprocesses to ensure the exploitation to the full potential of these novel
Scuola Normale Superiore, Laboratorio NEST
| 22 luglio
A classic never gets old
The Einstein relation between stimulated emission, many aspects of which can be understood classically,
and spontaneous emission, which it is generally agreed cannot be understood classically, can be seen
as the origin of quantum optics. In this talk we show that similar relations can be found in nonlinear
optics, starting with the generation of photon pairs by parametric fluorescence. This offers a new
perspective on the physics unifying classical and quantum integrated optics.
Università degli Studi di Pavia
| 28 luglio
Cross-Spectrum Measurement of PM Noise in the Presence of AM Noise
We measure the PM noise of an oscillator by comparing it with two independent references
(synthesisers), and by using two separate phase meters (mixers). The cross spectrum method
enables the rejection of the background noise, and provides enhanced sensitivity. However, AM
noise can result in serious under-estimation of the DUT noise, which is of course
Let us denote with c(t) the physical quantity to be measured (oscillator PM noise), with a(t)
and b(t) the background of the two instruments, and with x(t) = c(t)+a(t) and y(t) = c(t)+b(t)
the signals available at the instrument outputs. Assuming that the process are stationary and
ergodic (the physical experiment is repeatable and reproducible) and that the two instruments
are independent, the average correlation of x and y gives the statistical properties of c(t). The
single-channel noise is rejected proportionally to the square root of the number m of averages,
and ultimately to the square root of the measurement time.
A major problem has been discovered recently, that the oscillator AM noise results in cor-
related noise at the two outputs x(t) and y(t), and ultimately in a systematic error in the
measurement of the oscillator PM noise. The eect of AM noise can be either correlated or
anti-correlated. In the latter case, the DUT noise is under-estimated.
We will review the cross spectrum method, and discuss the eect of AM noise.
FEMTO-ST Institute, Dept. Time and Frequency
CNRS / École Nationale Supérieure de Mécanique et des Microtechniques (ENSMM) /
Université de Franche-Comté (UFC), Besançon, France
| 8 settembre
Research activity for humidity standards at NMIJ: Development of trace-moisture standard
National Metrology Institute of Japan (NMIJ)
National Institute of Advanced Industrial Science and Technology (AIST)
| 30 settembre
Long-range paired Kitaev chains
I discuss a generalization of the Kitaev Ising chain with long-range paring term, both with
periodic and open boundary conditions. The model is exactly solvable in terms of Bogoliubov excitations.
It is possible to identify a standard regime where the system behaves similarly to the usual
Ising spin chainand an exotic long-range regime where the correlation functions are power-law
decayingalso in presence of a non vanishing mass gap, the area law for the Von-Neumann entropy
is violated and the velocity of the excitations is diverging.
I also discuss the evolution of Majorana edge states decreasing the power-law exponent of the pairing.
At the end I comment shortly on the effects by a long-range hopping term.
Université de Strasbourg, France
| 27 ottobre
Deterministic Generation of Multiparticle Entanglement by Quantum Zeno Dynamics
Multiparticle entangled quantum states, required as a resource in quantum-enhanced metrology and
quantum computing, are usually generated by unitary operations exclusively, while carefully shielding
the system from any coupling to the environment. Recent developments in quantum technology show that
powerful new forms of quantum dynamics can be obtained when this dichotomy is abandoned and environment
coupling is used as part of the state generation. In this context we experimentally demonstrate the use
of Quantum Zeno Dynamics, based on non-destructive measurement with a high-finesse optical cavity, to
deterministically generate different multiparticle entangled states in an ensemble of 36 qubit atoms.
We perform quantum state tomography of the resulting state, we compare it to the separable state that
is observed without the simultaneous measurement, and quantify its depth of entanglement. We also measure
the properties of the entangled state as a function of the strength of the measurement. These results show
that QZD can be used as a versatile tool for fast and deterministic entanglement generation for quantum
engineering and quantum metrology applications.
I also discuss the evolution of Majorana edge states decreasing the power-law exponent of the pairing.
At the end I comment shortly on the effects by a long-range hopping term.
Laboratoire Kastler-Brossel, ENS CNRS