Workshop Q@TN - Quantum Science and Technology in Trento

For a physicists, quantum science is at the heart of his daily work. However, in recent years it has emerged that peculiar quantum phenomena can lead to new physics and new applications. Here we list the research activities performed at the Department where the concept of quantum science and technologies are specifically underlined.
1. Research activity on cold atomic gases, quantum fluids and Bose Einstein Condensation (work performed in collaboration with the CNR-INO unit of Trento):

• a. theory of quantum fluids and gases
• b. experiments with ultracold atoms
• c. experiments on atomic clocks

2. Research activity on integrated quantum photonics (work performed in collaboration with the CMM-FBK and CNR-INO unit of Trento):

• a. theory of quantum fluids of light
• b. experiments on integrated quantum circuits where entangled photon states are generated by nonlinear optics
• c. experiments on microring optical networks for gauge field implementations
• d. experiments on quantum random number generation

3. Research activity on quantum biology where the vibration theory of olfaction can lead to the development of a quantum noses
4. Research activity on quantum detectors based on cavity optomechanics for high precision measurements in gravitational physics
5. Research activity on transport, dissipation and decoherence of quantum electronic excitation in biological and organic macromolecular system
6. Research activity on nitrogen-vancancy complexes in diamond for ultra-sensitive probes (work performed in collaboration with the ITT unit of Rovereto)
7. Research activity on quantum simulator realized either with Bose Einstein trapped condensates or with topologically protected integrated photonic systems

For a physicists, quantum science is at the heart of his daily work. However, in recent years it has emerged that peculiar quantum phenomena can lead to new physics and new applications. Here we list the research activities performed at the Department where the concept of quantum science and technologies are specifically underlined.
1. Research activity on cold atomic gases, quantum fluids and Bose Einstein Condensation (work performed in collaboration with the CNR-INO unit of Trento):

• a. theory of quantum fluids and gases
• b. experiments with ultracold atoms
• c. experiments on atomic clocks

2. Research activity on integrated quantum photonics (work performed in collaboration with the CMM-FBK and CNR-INO unit of Trento):

• a. theory of quantum fluids of light
• b. experiments on integrated quantum circuits where entangled photon states are generated by nonlinear optics
• c. experiments on microring optical networks for gauge field implementations
• d. experiments on quantum random number generation

3. Research activity on quantum biology where the vibration theory of olfaction can lead to the development of a quantum noses
4. Research activity on quantum detectors based on cavity optomechanics for high precision measurements in gravitational physics
5. Research activity on transport, dissipation and decoherence of quantum electronic excitation in biological and organic macromolecular system
6. Research activity on nitrogen-vancancy complexes in diamond for ultra-sensitive probes (work performed in collaboration with the ITT unit of Rovereto)
7. Research activity on quantum simulator realized either with Bose Einstein trapped condensates or with topologically protected integrated photonic systems

The scientific competences of the Department of Mathematics of the University of Trento concerning Quantum Sciences and Technologies will be presented. Various groups of the Department of Mathematics are involved: Mathematical Physics, Mathematical Analysis, Stochastic Processes, Algebra, Geometry, including a post doctoral fellow and three PhD students. The researchers are connected with scientific interdisciplinary international leading groups and active in proposing scientific events. The scientific competences mainly regard Mathematical Techniques and Foundational Aspects of Quantum Theories and can be summarized as follows. General Formulation of Quantum theories in Hilbert space (Foundational and Axiomatic Approaches also in Real and Quaternionic Hilbert spaces) Researchers: R. Ghiloni, S. Mazzucchi, V. Moretti, A. Perotti. Quantum information and Quantum Control (Entanglement, Quantum Cryptography, Topological Quantum Computing). investigator: D. Pastorello. Integral Functional Formulations and Stochastic Approaches (Models of Decoherence and Quantum Zeno Effect, Semiclassical Limits and Path Integral on Curved Background) Investigator: S. Mazzucchi. Algebraic geometry technology for quantum information and entanglement (Tensor Decomposition Techniques). Researchers E. Ballico, A. Bernardi. Algebraic Formulation of Quantum Theories (QFT in Curved Background and Quantum Gravity). Researchers: R.Brunetti and V.Moretti.

Some recent publications

V. Moretti: Spectral Theory and Quantum Mechanics with an introduction to the Algebraic Formulation (Book) 752 pp (2013) Springer-Verlag
S. Albeverio, S. Mazzucchi: A unified approach to infinite-dimensional integration Reviews in Mathematical Physics 28 (2016), 1650005
R. Brunetti, K. Fredenhagen, K. Rejzner: Quantum gravity from the point of view of locally covariant QFT, Communications in Mathematical Physics 345 (2016), 741-779
A. Bernardi and I. Carusotto, Algebraic geometry tools for the study of entanglement: an application to spin squeezed states, Journal of Physics A, vol. 45, no. 10, Article ID 105304, 13 pages, 2012
I. Khavkine, V. Moretti: Analytic Dependence is an Unnecessary Requirement in Renormalization of Locally Covariant QFT, Communications in Mathematical Physics 344 (2016), 581-620
V. Moretti, D. Pastorello (2016) Frame functions in finite-dimensional quantum mechanics and its Hamiltonian formulation on complex projective spaces International Journal of Geometric Methods in Modern Physics 13, (2016) 1650013
R. Ghiloni, V. Moretti and A. Perotti: Spectral properties of compact normal quaternionic operators, in Hypercomplex Analysis: New perspectives and applications, Trends in Mathematics, Birkhauser, (2014)
D. Pastorello: Open-loop quantum control as a resource for secure communications, International Journal of Quantum Information 14 (2016) 1650010

The DISI (Department of Information Engineering and Computer Science) covers a broad range of research areas and topics in the framework of information technology and engineering.
This presentation will focus on three Q-related research activities carried out by DISI members.
In particular, the first part focuses on the proposal of a Quantum Genetic Optimization Algorithm, which is an early instance of the so-called Quantum Evolutionary Algorithms aimed to take advantage of quantum computation on a wide range of applications by running Genetic Algorithms on quantum architectures.
The second work, held in collaboration with D-Wave inc., aims at developing effective and efficient encodings for Propositional Satisfiability (SAT) and other NP-hard problems to be solved by D-Wave's quantum annealers. Finally, the third topic will present an innovative engineering paradigm, the so called System-by-Design, for the design of advanced materials and the solution of complex medical/industrial diagnostics problems thanks to the exploitation of quantum simulators and quantum sensors.

The Department of Industrial Engineering (DII) is composed of several groups of researchers in Materials, Biomaterials, Electronics and Mechanical Engineering working and collaborating together. Among the different research activities carried out at the DII, there are some which might be part of a collaboration network on quantum technologies in Trento. The following topics are particularly relevant:

• analysis of the optical properties of luminescent quantum dots (QDs) exposed to ionizing radiations like ion beams and high-energy photons. This activity, performed in collaboration with TIFPA, aims at the optical characterization of point defects, which could either enhance or quench the luminescence of QDs. From the point of view of quantum technology, in specific QDs irradiation induced defects can give rise to the formation of single photon emitting centers suitable for sources in quantum communication or quantum simulation systems
• design, modeling, fabrication, characterization and optimization of photodetectors and, particularly, of single photon avalanche diodes (SPAD), which are keystones in quantum technology for the detection of single photons in all the possible applications. At DII there are researchers who have significantly contributed, in collaboration with FBK, to the development of SPADs in both full custom and CMOS technologies. Moreover, at DII a great deal of work is currently being performed for the noise and sensitivity optimization of such devices
• study of the energy transfer process in organic and biological systems. The energy transfer mechanism in biomolecules is cited in the document describing the quantum technology roadmap since recent studies evidenced that quantum mechanical processes could describe the phenomena better than the semi-classical approaches used so far. The deepening of such effects could help in the design of molecular systems based on purely quantum effects for quantum sensors and energy harvesting
• functionalization of carbon nanotubes and quantum dots. A chemistry group at DII has developed remarkable expertise in the functionalization of nanostructures. Recently, it has been demonstrated that single walled carbon nanotubes are suitable for the production of single photons under electrical excitation, and the production rate and yield can be modulated by a proper functionalization of the nanotube surface

Tools and instruments are present at DII that can be used for the characterization of nanostructures and materials. Among the most important we can cite:

• an electron microscopy platform, including scanning electron microscopes, equipped with X-Ray spectroscopy systems, and a transmission electron microscope. This instrument is particularly designed for analytical electron microscopy studies, involving imaging, chemical and crystallographic investigations. Combined analyses of these data, using original and newly developed approaches, provide important materials investigation tools down to the nanometric length scale
• a Nuclear Magnetic Resonance spectroscopy (SS-NMR) facility at the “Klaus Müller” Magnetic Resonance Laboratory (DII), which is one of the few centers in Northern Italy devoted to the application of NMR in the field of materials science. Currently the facility is equipped with two NMR solid state and liquid state spectrometers (9,4 and 7 T magnetic fields, i.e., proton frequencies of 400 and 300 MHz), an electron paramagnetic resonance (EPR or ESR) spectrometer and an earth field NMR for imaging. SS-NMR is suitable for the characterization of structure, interfaces and molecular dynamics of solids, assessing the relations between structure and physico-chemical properties. Both solid and liquid NMR allow to study the growth of building blocks and the functionalization of nanostructures
• Atomic Force Microscope (AFM) Solver PRO (NT-MDT) equipped for conventional scanning 90×90×4µm³ and for high resolution scanning 4×4×1µm³. The AFM has an attachment for STM and can perform measurements in liquids and in acoustic AFAM mode. A temperature controller allows to perform measurements on samples up to 150 °C
• confocal microscope Nikon A1 with galvanometric scanner coupled to an excitation unit suitable for the following laser wavelengths: 405 nm, 457 nm, 477 nm, 488 nm, 514 nm, 561 nm and 638 nm. The signal is processed by 4 PMTs and by a spectral detector with 32 channels (2.5 nm of resolution). The system is coupled to an inverted microscope ECLIPSE Ti-E with motorized bench. This system can be coupled to spectrometers through optical fibres and it is suitable for single QD spectroscopy measurements

In FBK both the ICT and CMM research centres plan a significant involvement in the activities of the QT cluster of Trento, according to their specific skills and interests and in synergy with the other members of the cluster. Specifically, the ICT has identified research lines in formal verification and testing of quantum programs and quantum deep learning. The research of the CMM will cover simulations and conceptual design of quantum systems (sensors, QNRG, atom chips) and their fabrication in the MN Facility.
This second ability (fabrication) is also available to implement in hardware solutions research concepts of the other groups involved in Q @ TN.
The intended research topics and methods in QC, virtual atoms, QRNG, sensors, photonics, etc that will see the involvement of the FBK groups are here presented.

Several competences are present at IFN-CNR, from the theory and simulation of quantum processes and protocols, to the design, fabrication, characterization, and testing of novel materials, quantum devices, integrated chips, and systems, to applications covering the four pillars of the Quantum Manifesto. Inside this set of competences IFN-Trento contributes with material synthesis and fabrication of glass-based photonic structures by sol-gel and RF sputtering techniques, as well as with several characterization techniques.

IFN-Trento contributes

In the experimental study of "quantum materials":

• nano "quantum-objects" or artificial atoms, such as defect- or chromophore-activated nanoparticles and nanocrystals, classical quantum dots but also ZnO, HfO₂, SnO₂, NV centers in diamond
• photonic devices based on size-controlled nanoobjects integrated in photonic crystal structures and waveguides for photon spin-qubits interactions
• experimental study of homogeneous and inhomogeneous line broadening of rare-earth ions in a crystal matrix for rare-earth ion based quantum computing
• optical, spectroscopic and structural characterization of quantum materials, nanostructures and devices

In the "materials and technology platforms":

• ZnO, HfO₂, SnO², rare-earth-doped activated nanocrystals, glasses, colloids and glass-ceramics
• quantum dots; artificial opals; 1D photonic crystals

IFN-Trento is expected to be active in the pillars iii) Quantum sensors and metrology (photonic networks in bulk diamond for spin-based sensing; single photon emission and detection for quantum networking, single atoms for quantum atomic clocks); iv) Quantum computing (rare-earth ion and luminescent species selective spectroscopy as quantum processor).
Consolidated local collaborations in this area: CMM-FBK is driving the numerical approach in the framework of the synergic activity on quantum states for single ion emission/detection.
Consolidated national collaboration in this area: IFN-Milano is driving the synergic activity on waveguides and NV centers in diamond, micromachining for quantum systems, nanoscale resolution magnetometers and single photon sources.
Consolidated international collaboration in this area: ENSSAT Lannion for WGMs spherical resonators and single photons in resonance cavities.
Other specific common activities are active with: DF, DII, DICAM.

The BEC Center was created in 2002 with the goal to promote research activities in the field of quantum gases and related areas, and to strengthen the interdisciplinary links and the scientific collaborations among theoretical and experimental groups around the world. In these years, the BEC Center has gained a solid international reputation as one of the leading groups in the theory of quantum gases, superfluids, and quantum optics. The recent activation of an experimental laboratory on ultracold atoms has opened new perspectives, allowing for a good balance of theories and experiments developed side by side. The activities of INO-CNR within the BEC Center benefit from strong collaborations with the Department of Physics of the University of Trento.
Ultracold gases, quantum optics, quantum fluids of light are among the most promising platforms for quantum technologies. They represent an ideal environment to test the role of quantum coherence and entanglement, providing tools for quantum simulators and precise measurements. Quantum techniques based on cold atoms and lasers have boosted a new generation of sensors, such as gravimeters, accelerometers, gyroscopes, and atomic clocks.
In the INO-BEC BEC Center, we focus on both fundamental and applied physics, with an interdisciplinary perspective. At present the main theoretical themes are: superfluidity, matter waves, coherence and disorder, strongly interacting Fermi gases, quantum mixtures and spinor gases, spin-orbit coupled gases, low dimensional physics, atoms in optical lattices, quantum Monte Carlo simulations, quantum fluids of light, quantum magnetism and topological quantum states, and analog models of quantum gravity. In the experimental laboratory we are currently studying: quenched BEC and Kibble-Zurek mechanism, structure and dynamics of solitonic vortices, bouncing and reconnecting vortex lines, spin-dipole oscillations in spinor BEC, equation of state of a dilute Bose gas, novel sources for atomic clocks, new cooling and imaging techniques, and quantum simulations of high energy physics. As regards optical atomic clocks, the activities in Trento aim at developing a source of cold Strontium atoms at conditions of temperature and confinement suitable to the accurate interrogation of the optical clock transition. Once operational and tested, the atomic source will be transferred to INRIM in Torino for operation and characterization in the final optical clock setup. We are currently working on the design and assembly of the cold atomic source, as well as the assembly of the computer controlled electronics required for the preparation and interrogation of the atomic sample.

The spin-dependent fluorescence of negatively charged Nitrogen-Vacancy centers in diamond has been exploited for precision magnetometry and to probe the magnetic properties of materials.
The sensitivity to their magnetic environment at room temperature and the excellent biocompatibility of diamond make NV centers ideal sensors for bioimaging.
Our interest is focused on the development of this technology for sensing in biomedical applications, e.g. to probe the activity of large ensembles of cells, like neurons, in tissues and cell cultures. To this end, we are exploring nanostructured diamond and nanocrystals as a means to target specific cellular compartments.
Moreover, we are investigating methods to probe the interactions of NV centers with nuclear spins for spatially-resolved Optically Detected Magnetic Resonance, and to improve sensitivity in NMR detection.

During the last year, TIFPA installed and now manages the proton beam irradiation facility at the APSS Proton therapy center in Trento, where energy can be varied from 70 to 220 MeV, and several different beam setups can be realized. Application of this beam for research in Quantum Technology can be multifold. E.g., defect implantation techniques in different materials with ions at unconventional energies can be studied, and nanodosimetric properties of quantum dots may be tested.
In addition to the proton beam, TIFPA has recently installed also a state-of-the art X-ray facility in its lab at the premises in the Department of Physics, University of Trento, where Energy can be raised up to 200 kV. This tool also offers relevant possibilities for investigating quantum device properties and implementation with photons.
Finally, beside experimental features, TIFPA research on nanoscale Monte Carlo simulation for protons and electrons propagation in materials, can provide useful insights supporting these studies.
A short overview of these possibilities will be presented.

We describe the two unique ways in which ECT* can contribute to the Q @ TN initiative.
On the one hand, we briefly review the scientific expertise of the in-house research group including the recently merged "Laboratorio Interdisciplinare di Scienza Computazionale".
On the other hand, we describe the coordination activities in the quantum technologies area carried out since 2005 and that have lead to the recent launch of the Quantum Technologies flagship initiative.