University of Malta
 

Programme
UOM Main Page
 
 
 
Apply - Admissions 2016
Newspoint
Campus Map button
Facebook

The programme of the conference is as follows, we apologize to any talks not selected, this was due to the very high number of applications: 

Monday

18:00 - 19:30
Reception (Hotel Venue The Victoria - William Shakespeare Room, Level 1)


Tuesday

09:00 (j)
Registration
09:40 (j)
Welcome Address

First Joint Session - Chairpersons: Silke Britzen and Angelo Bassi

10:30 (j)

Joe Silk - Cosmological Implications of Black Holes

11:30 (j)

Markus Arndt - Quantum coherence, decoherence and the role of gravity in matter-wave experiments with molecules and nanoparticles

De Broglie interferometry with macromolecules, clusters and other kinds of nanoparticles explores the boundary between experimentally tested quantum mechanics and classical physics by gradually increasing the size and complexity of objects whose coherent delocalization can still be proven.


We will discuss three recent experiments performed in our group at the University of Vienna and how to extrapolate them to masses where gravity starts becoming influential: far-field diffraction of fluorescent molecules at ultrathin gratings demonstrates the wave-particle duality in a particularly conspicuous and didactical way1,2, as it allows to image the stochastic arrival of single molecules in real-time as well the formation of the deterministic ensemble interferogram in the same image. Near-field interferometry in the Kapitza-Dirac-Talbot-Lau design has led to the current mass record in quantum delocalization experiments 3,4 with new results emerging. A novel matter-wave interferometer that operates with pulsed ionization gratings is being discussed, as it is expected to be best adapted for demonstrating translational quantum coherence for the most massive particles 5-7. 


We will discuss the practical complexity limits of matter-wave interferometry, including kinematic effects, phase averaging, decoherence and non-standard models of quantum mechanics. It turns out that classical gravity and the rotation of the Earth can cause significant dephasing in high-mass interferometry with particle beams of finite velocity dispersion. We discuss the relevance of long coherence times and ways to preserve them in a micro-gravitational environment.
 

12:30
LUNCH

First afternoon session - Chairperson: Jackson Levi Said

14:00

Tejinder Singh - Removing time from quantum theory : implications for the measurement problem

There are reasons which suggest the existence of an equivalent reformulation of quantum theory which does not refer to time. A consequence is that quantum theory is a limiting case of a stochastic nonlinear theory, with the nonlinearity becoming significant at the Planck mass scale. The nonlinearity can in principle explain why the wave-function collapses during a measurement. Ongoing and planned experiments can verify or rule out the existence of such a nonlinearity. 

14:30

Omri Gat - Entangled Schroedinger cats in circuit QED

Superconducting circuits process quantum information by coupling Josephson junction qubits with electromagnetic modes. Qubit-mediated interaction between two modes prepared in highly-excited coherent states generates two-mode entanglement of macroscopically distinct wave packets. We show that the two-mode state exhibits two types of entanglement, Bell-like and two mode squeezing, and that there is a trade-off between the degree of entanglement and Bell inequality violation in each entanglement variable. Filtering by weak quadrature measurement produces a superposition of products of squeezed coherent states, that is the CQED version of entangled Schroedinger cats. 

15:00
COFFEE BREAK

Second afternoon session - Chairperson: Egidijus Norvaisas 

15:30

Nicolas Gisin - Quantum nonlocality based on finite-speed influences leads to signalling

The experimental violation of Bell inequalities using space-like separated measurements precludes the explanation of quantum correlations through causal influences propagating at subluminal speed. Yet, it is always possible, in principle, to explain such experimental violations through models based on hidden influences propagating at a finite speed v>c, provided v is large enough. Here, we show that for any finite speed v>c, such models predict correlations that can be exploited for faster-than-light communication.


This superluminal communication does not require access to any hidden physical quantities, but only the manipulation of measurement devices at the level of our present-day description of quantum experiments. Hence, assuming the impossibility of using quantum non-locality for superluminal communication, we exclude any possible explanation of quantum correlations in term of finite-speed influences, see arXiv:110.3795. 

16:00

Catalina Oana Curceanu - A glance into the Pandora Box of quantum mechanics: Pauli Exclusion Principle violation and spontaneous collapse models experimental tests

In spite of its enormous success, or maybe exactly for this, Quantum Mechanics still hides many mysteries. We shall explore two: the spin-statistics connection and the collapse of the wave function. Experimental undergoing tests of the Pauli Exclusion Principle violation will be discussed, together with future plans to measure the spontaneous emission of X rays predicted in collapse models (CSL).

We present a method of searching for possible small violations of the Pauli Exclusion Principle (PEP) for electrons, through the search for "anomalous" X-ray transitions in copper atoms, produced by "fresh" electrons (brought inside the copper bar by circulating current) which can have the probability to do the Pauli-forbidden transition to the 1 s level already occupied by two electrons. We describe, then, the VIP (VIolation of PEP) experiment which took data at the Gran Sasso underground laboratories, searching for these Pauli-prohibited transitions. 

The goal of VIP is to test the PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10**-29 - 10**-30,  improving the previous limit by 3-4 orders of magnitude.

We report achieved experimental results and briefly discuss some of the implications of a possible violation, together with future plans to gain other about 2 orders of magnitude in the estimation of the probability of PEP violation.

We will then present an idea to use a similar experimental technique to measure the spontaneously emitted X rays predicted  in the framework of collapse models (GRW theory, dynamical reduction models). 

We shall have a short glimpse into the Pandora’s box of Quantum Mechanics, where – apart of Schrodinger cat – other interesting features might still be hiding. 

16:30

Jyrki Piilo - Nonlocal memory effects in the dynamics of open quantum systems

We study a model of two entangled photons interacting locally with two dephasing environments. It is shown that initial correlations between the local environments can generate a nonlocal quantum process from a local interaction Hamiltonian. While the global dynamics of the two-photon polarization state exhibits strong memory effects, the induced local dynamics of either of the two photons is found to be Markovian. A direct connection between the degree of memory effects and the amount of correlations in the initial environmental state is derived. The results demonstrate that, contrary to conventional wisdom, enlarging an open system can change the dynamics from Markovian to non-Markovian. 

17:00

END of day one 


Wednesday

Second Joint session - Chairpersons: Silke Britzen and Angelo Bassi 

  10:00 (j)

GianCarlo Ghirardi - Collapse Theories: a viable solutions to the problems of quantum mechanics

A synthetic review of some of the puzzling formal and physical aspects of quantum mechanics which are relevant for the quantum conception of reality, will be presented. In particular attention will be paid to the linear character of the theory and to the phenomenon of entanglement with the related nonlocal aspects. This will offer the opportunity to discuss the measurement problems and to critically review some of the most relevant proposals to overcome it with particular reference to the so-called Collapse Models. A discussion of their general features as well as of the problems they have to face, with specific reference to the relativistic requests, will be presented.

11:00 (j) Greg Landsberg - TBA
12:00LUNCH

First afternoon session - Chairperson: Bassano Vacchini 

13:30Andreas Buchleitner - Quantum transport in biological functional units: noise, disorder, structure
14:00

Thomas Durt - Fundamental aspects of Time in Quantum Mechanics and Meson Phenomenology

Mesons illustrate fundamental quantum properties such as the superposition principle (for instance in kaon oscillations), and their phenomenology also appeared very useful in the past for measuring CP-violation related effects.

More recently, mesons were also useful for testing decoherence and entanglement related effects.

The aim of our talk is to show that mesons could also be useful for revealing and/or studying fundamental aspects of Time in the quantum theory, such as the existence of a Time Operator (and also of the so-called Time Superoperator). 

14:30COFFEE BREAK

Second afternoon session - Chairperson: Mario Ziman 

15:00

Manfred Niehus - Experimental progress in decoherence studies in free space photonics and optical microfibers

We report about the experimental progress we achieved in decoherence studies both in free space and optical microfiber setups, based on polarization entangled photon pairs. 

In free space, the objective of our work is, at least, to reproduce results achieved recently by other groups, and demonstrating experimentally the transition from Markovian to Non-Markovian dynamics. 

Concerning optical microfibers, the objective is a proof-of-concept to show that these waveguides can be used to manipulate and alter the decoherence dynamics. 

15:30

Christos Efthymiopoulos - Chaos in de Broglie - Bohm dynamics and its physical

Quantum systems with moving quantum vortices exhibit chaotic behavior of their de Broglie - Bohm trajectories. The dynamical mechanisms behind the appearance of chaos will be presented. However, we find that in many systems chaos is not complete, but there are also many regular de Broglie - Bohm trajectories. This effect poses limitations on the effectiveness of the so-called `quantum relaxation' effect, that has been proposed in order to interpret dynamically the approach of quantum systems to Born's rule. We will discuss quantitative estimates regarding the rate and/or obstructions to relaxation as related to the degree of chaos in quantum systems. We will finally discuss the role of quantum vortices in scattering and diffraction phenomena.

16:00COFFEE BREAK

Third afternoon session - Chairperson: Sandor Imre 

16:30

Jakub Zakrzewski - Extraction of information from dynamics of strongly correlated states

An extension of the time-dependent Density Matrix Renormalization Group (t-DMRG), also known as Time Evolving Block Decimation algorithm (TEBD), allowing for the computation of excited states of one-dimensional many-body systems is presented. Its practical use for analyzing the dynamical properties and excitations of the Bose-Hubbard model describing ultracold atoms loaded  in an optical lattice from a~Bose-Einstein condensate is shown.

This allows for a deeper understanding of nonadiabaticity in experimental realizations of insulating phases - an important aspect for the future prospects of quantum simulators. 

17:00

Daniel Sudarsky - The quantum origin of the seeds of cosmic structure and the need for new physics

The observations of the first traces of cosmic structure in the Cosmic Microwave Background are in excellent agreement with the predictions of Inflation. However as we shall see, that account is not fully satisfactory, as it does not address the transition from an homogeneous and isotropic early stage to a latter one lacking those symmetries. We will argue that a new aspect of physics must be  call upon if we want to account for such transition and that Quantum Gravity might be the place from where this new physics emerges. Moreover we will show that the observations can be used to  constrain the various phenomenological proposals made in this regard. 

17:30

END of day two

18:00

Bus from conference venue to tour of L-Mdina and conference dinner, more information on Conference dinner page


Thursday

Third Joint Session - Chairpersons: Silke Britzen and Angelo Bassi 

  10:00 (j)  Peter Biermann - TBA
11:00 (j)
Jean Bricmont - From the microscopic to the macroscopic world and the origin of irreversibility
12:00
LUNCH

First afternoon session - Chairperson: Yuji Hasegawa 

13:30

Beatrix Hiesmayr - Revealing Bell's Nonlocality in Particle Physics?!

To obtain the whole picture on the phenomenon of entanglement also systems at different energy scales have to be considered. Entangled neutral kaons have turned out to be specially suited to test foundations of quantum mechanics in a way only provided by this system. Only recently a first conclusive experimental test to reveal Bell's nonlocality was found. In the article [Hiesmayr et al., Eur. Phys. J. C (2012) 72:1856] the authors succeeded in deriving a new Bell inequality taking into account the decay property while not spoiling the conclusiveness and, simulataneously, garanteeing its testability. Moreover, the proposed test is experimentally feasible with current technology, e.g. with the KLOE detector at the accelerator facility DAPHNE in Italy.  

14:00
Lajos Diósi - Classical-Quantum Coexistence: a `Free Will' Test
14:30
COFFEE BREAK

Second afternoon session - Chairperson: Angel Santiago Sanz  

15:00

Giovanni Ciccotti - A pseudo-quantum description of (classical) vacancy diffusion in crystals

We introduce an observable field to describe the dynamics of a single vacancy in a crystal. This field is the density of a pseudo quantum wavefunction representing the vacancy, which, in turn, is the ground state eigenfunction of an Hamiltonian associated to the potential energy field generated by the atoms in the sample. In our description, the $\hbar^2/2 m$ coefficient of the kinetic energy term is a tunable parameter that makes the density localized in the regions of relevant minima of the potential energy field. Based on this description, we derive a set of collective variables that we use in rare event simulations to identify the vacancy diffusion paths in a 2D crystal. Our simulations reveal, in addition to the simple and expected nearest neighbor hopping path, collective migration mechanisms of the vacancy. These mechanisms involve several lattice sites and produce a long range migration. Finally, we also observed a vacancy induced crystal reorientation process. 

15:30
Ward Struyve - Semi-classical approximations based on the de Broglie-Bohm theory
16:00
COFFEE BREAK

Third afternoon session - Chairperson: Gheorghe-­Sorin Paraoanu 

16:30

Marco Genovese - Recent experimental progresses in testing Quantum Mechanics 

Quantum Mechanics represents nowadays one of the pillars of modern physics: so far a huge amount of theoretical predictions deriving from this theory has been confirmed by very accurate experimental data, while the theory is at the basis of a large spectrum of researches ranging from solid state physics to cosmology, from bio-physics to particle physics. Furthermore, in the last years the possibility of manipulating single quantum states has fostered the development of promising quantum technologies as quantum information (calculus, communication, etc.), quantum metrology, quantum imaging, ...

Nevertheless, even after a pluri-decennial debate many problems related to the foundations of this theory persist, like non-local effects of entangled states, wave function reduction and the concept of measurement in Quantum Mechanics, the transition from a microscopic probabilistic world to a macroscopic deterministic world described by classical mechanics (macro-objectivation) and so on. Problems that, beyond their fundamental interest in basic science, now also concern the impact of these developing technologies.

In this talk, after a short summary of the present discussion concerning some of these problems, we present some recent experimental works in the field.

In particular, some specific experiment realized at INRIM will be described in some detail (concerning tests of specific local realistic models, wave particle duality, …).
The first experiment to be described regards the testing of two specific, restricted local realistic models, properly built for experiments with entangled photons; the interesting feature of these models is the fact that they are free from the detection loophole, thus they don’t rely on the fair sampling assumption (the quantum efficiency of the system plays a role in the inequalities built for these models). The experimental data collected violated these inequalities, showing instead a perfect agreement with Quantum Mechanics predictions. The second one is a non-classicality test at the single particle level. 

17:00

Spiros Skourtis - Biological electron transport processes

Electron transfer reactions are ubiquitous in biology. Biological electron transfer mechanisms range from tunnelling to thermally activated hopping. Due to the nature of biomolecules, molecular motion (structural fluctuations) is an important determinant of the electron transfer rate. I give a brief introduction to the theory and simulation of biological electron transfer rates and discuss similarities between biological electron transfer and small molecule /molecular wire electron transport mechanisms. In the final part of the talk I discuss recent work about the control of electron transport in biological and small molecule devices. 

17:30
END of day three


Friday

First morning session - Chairperson: Beatrix Hiesmayr 

10:00

Salvador Miret-Artés - Quantum (Bohmian) Stochastic Trajectories

Stochasticity plays an imprtant role in many problem found in classical and quantum mechanics. Here we would like to introduce, in a simple way, the concept of quantum (Bohmian) stochastic trajectory by analyzing the free evolution of one and two wave packets in presence of a flat surface considered as a thermal bath. Decoherence and the Zeno effect will also be discussed.

10:30

Irene Burghardt - Hierarchical effective-mode decomposition for non-Markovian quantum environments

This talk summarizes our recent developments of reduced-dimensional representations of non-Markovian environments, based upon the construction of Mori type effective mode chains [1-3]. The sequences of coupled effective modes, which are generated by suitable coordinate transformations from spin-boson type models, absorb the cumulative effects of the system-bath coupling and can be shown to sequentially resolve the dynamics as a function of time. Truncation of the chains at successive orders generates a family of approximate spectral densities which approach the true spectral density with increasing accuracy [1,3]. Convergence can be explicitly demonstrated in terms of the properties of the residual spectral densities which approach a quasi-Ohmic limit [3]. Overall, the approach provides a very general strategy for the embedding of non-Markovian environments into an enlarged set of variables. An extension to correlated environmental fluctuations is straightforward. Applications are presented for non-adiabatic dynamics and excitation energy transfer in extended molecular systems [2]. Here, decoherence is typically found to set in with a delay, beyond the shortest time scale which is determined by few effective modes.

[1] K. H. Hughes, C. D. Christ, I. Burghardt, J. Chem. Phys. 131, 024109 (2009); ibid. 131, 124108 (2009).
[2] H. Tamura, J. G. S. Ramon, E. R. Bittner, I. Burghardt, Phys. Rev. Lett. 100, 107402 (2008), H. Tamura, I. Burghardt, M. Tsukada, J. Phys. Chem. C 115, 9237 (2011).
[3] R. Martinazzo, B. Vacchini, K. H. Hughes, I. Burghardt, J. Chem. Phys. 134, 011101 (2011), R. Martinazzo, K. H. Hughes, I. Burghardt, Phys. Rev. E 84, 030102(R) (2011). 

11:00
COFFEE BREAK

Second Morning session - Chairperson: Petros Wallden 

11:30

Yuji Hasegawa - Uncertain relation studied in neutron’s successive spin-measurements

The uncertainty principle is certainly one of the most famous and important aspects of quantum mechanics: Heisenberg first suggested a limitation of joint measurements of canonically conjugate variables due to the back action of measurement. However, known rigorous proofs justify the prediction, that the product of the measurement error and disturbance caused by the measurement is not less than a bound set by the commutator, only under limited circumstances. Recently a universally valid relation between the error and the disturbance has derived by Ozawa. In this talk, a neutron optical experiment is reported that measures the error of a spin-component measurement and the disturbance caused on another spin-component measurement. The experimental results exhibit that the error and the disturbance completely obey the new relation but violated the old one in a wide range of experimental parameters. The solution of a long-standing problem to describe the relation between the measurement accuracy and the disturbance caused by that measurement is discussed. 

12:00
LUNCH

First afternoon session - Chairperson: Catalina Curceanu 

13:30

André Xuereb - Quantum mechanics at the meso-scale

The past decade has seen the field of optomechanics, the use of light to control the motion of mechanics at the micro-scale, steadily gaining traction. Recent progress hints that experiments may soon start moving away from proofs of principle and towards tests of quantum mechanics at larger and larger mass scales. involving, e.g., mechanical Schrödinger cats, or entangled states of a mirror with a light field.

 In this talk I will briefly introduce the main theoretical tools that are used in the description of optomechanical systems, and then go on to discuss some of our recent work dealing with the possibility of observing genuine multipartite entanglement between light fields and mesoscopic mechanical oscillators in experimentally-accessible systems.

14:00

Adrian Kent - The Quantum Landscape

I describe new classes of generalizations of the quantum theory of a closed system that make testably different predictions from standard quantum theory, and examine the theoretical and experimental implications.

14:30
COFFEE BREAK

Second afternoon session - Chairperson: Daniel Braun 

15:00

Antonio Di Domenico - The Quantum Mechanics and discrete symmetries of neutral K mesons

The neutral kaon doublet is one of the most intriguing systems in nature.
Entangled pairs of neutral K mesons produced in φ decays offers a unique possibility to perform very precise tests of fundamental discrete symmetries in nature, as well as of basic principles of quantum mechanics.The most recent results will be reviewed and perspectives in the field will be discussed.  

15:30

Nikola Buric - Emergence of classical systems from constrained quantum background.

Coarse-grained description of a quantum system is mathematically described as a constrained Hamiltonian dynamics. It is seen that the evolution of properly coarse-grained systems preserves constant and minimal quantum fluctuations of the fundamental observables. This leads to the emergence of the corresponding classical system on a sufficiently large scale. The procedure is utilized to establish a consistent description of hybrid quantum-classical systems. Dynamics of the quantum measurement process is discussed as a relevant example. 

16:00
COFFEE BREAK

Third afternoon session - Chairperson: Angelo Bassi 

16:30

Thomas Filk - A Chain of Coupled Pendula Leading to Quantum Relativity

Any conceptually closed quantum theory which addresses the problem of a quantized space-time structure faces the task of including ``rulers'' and ``clocks'' as dynamical subsystems. In view of this challenge, the Sine-Gordon theory can serve as a non-trivial toy model with many profound features:

1) The classical (non-quantum) Sine-Gordon theory can be formulated as the continuum limit of a chain of pendula, i.e., as a Newtonian system which in the continuum limit becomes Lorentz invariant. 2.) The non-trivial solutions of the Sine-Gordon equation - solitons and breathers - can serve as intrinsic measures for spatial and temporal distances. The transition from extrinsic measures (used by an external, Newtonian observer) to intrinsic measures (the widths of solitons and the periods of breathers) corresponds to the transition from the Lorentz invariant Newtonian theory (the chain of coupled pendula in the continuum limit) to an intrinsically relativistic (Minkowski) structure of space and time.
3.) As the Sine-Gordon theory is integrable both as a classical theory as well as a quantum theory (using classical and quantum inverse scattering methods), many of the non-trivial concepts related to dynamical rulers and clocks can be studied explicitly.

The first part of my talk will describe the transition from the chain of coupled pendula to a relativistic theory and the relevance of solitons and breathers in the physical interpretation of this transition. The second part will be an introduction to the quantum properties of the Sine-Gordon theory as well as some speculative ideas about the role of ``quantum clocks'' and ``quantum rulers'' in a complete theory of quantum space-time.

17:00

Egidijus Norvaisas - Selfconsistent canonically quantized SU(3) Skyrme Model for Baryons

The traditional approach is to consider SU(3) Skyrme model semiclassically as a rigid quantum rotator with the profile function being fixed by the classical solution of the SU(2) Skyrme model. In this work the canonical quantization of the model is performed in terms of the collective coordinate formalism and leads to the establishment of a purely quantum corrections of the model. These new corrections are of a fundamental importance. They are crucial in obtaining stable solitonic solutions of the quantum SU(3) Skyrme model, thus making the model selfconsistent. The canonical quantization realize the T.H.R. Skyrme‘s conjecture that „mass may arise as a selfcosistent quantal effect“. Such treatment of the model conversely to the semiclassical case leads to a family of the stable solitonic solutions that describe the baryon octet and the decuplet and reproduces the experimental values of their masses and other physical parameters. 

17:30
Concluding remarks
18:00
END of conference

(j) - Common session with Black Hole conference


This will be included in the welcome pack along with an information pack available here.

Calendar
Notices
Members of ISSA join the KiDS Consortium
Members of ISSA, in collaboration with the Department of Physics, has recently joined the KiDS Consortium
University of Malta Awarded Title: 'CUDA Research Center'
The Institute of Space Science and Astronomy (ISSA), in collaboration with the University of Malta’s Department of Physics and the Faculty of Information and Communications Technology, announces that the University of Malta has been awarded the title of 'CUDA Research Center' by NVIDIA.
 
 
Last Updated: 21 April 2012

Log In back to UoM Homepage