The faculty members of the Atomic Molecular and Optical (AMO) Physics Section are Prof. I.K. Kominis and Prof. T.P. Rakitzis, and the retired faculty Prof. Emer. D. Charalambidis, Prof. Emer. C. Fotakis, Prof. Emer. P. Lambropoulos and Prof. T.J.M. Zouros. Several members of the AMO Physics Section are affiliated with the Institute of Electronic Structure and Laser at the Foundation for Research and Technology - Hellas, which hosts additional research groups working on several aspects of theoretical and experimental AMO.
The Physics Department AMO Section conducts cutting-edge experimental and theoretical research, offering undergraduate and graduate students hands-on training and deep analytical skills required to perform sophisticated experiments as well as theoretical calculations in a broad array of AMO fields, like lasers and photonics, electronics and data acquisition and analysis, vacuum technology, atomic and molecular physics, chemical physics and biophysics, classical and quantum optics, quantum technology and quantum information.
Attosecond Science & Technology Laboratory (A-S&T Lab)
Confinement of a system to the dimensions of an atom, according to the Uncertainty Principle, results into motion with characteristic times in the attosecond regime. Capturing such ultrafast motion requires radiation pulses in this time scale. Synthesis of attosecond pulses requires, according to the Superposition Principle, spectral widths that exceed the width of the visible and longer wavelength radiation spectrum, i.e. it requires coherent broadband extreme ultraviolet (XUV) and/or x-rays. Short wavelengths, according to the diffraction principle, offer high spatial resolution. Thus XUV (x-ray) attosecond pulses provide the highest possible combination of spatiotemporal resolution. The A-S&T Lab focuses its activities in the development of intense attosecond radiation sources, based on the non-linear interaction of laser radiation with gaseous media, their characterization and their exploitation in time domain applications and strong field physics. Developing attosecond beamlines that are reaching XUV peak power of the order of 10 GWatt and sub-femtosecond pulse duration, non-linear processes induced solely by the XUV radiation become feasible. The A-S&T Lab is exploiting such processes in the temporal characterization of the attosecond pulses, in the investigation of ultrafast dynamics using the XUV-pump-XUV-probe technique, in the investigation of multi-XUV-photon multiple ionization and in the demonstration of strong field effects in the XUV spectral region. A further activity of the A-S&T Lab is its contribution in the establishment and implementation of large European and national user research infrastructures.
More information can be found here.
Laboratory for Quantum Physics and Quantum Biology
Quantum sensing is one of the major pillars of modern quantum technology, aspiring to transform the intricacy of quantum microcosm into useful technology. For example, atomic magnetometers, which are a major paradigm of quantum sensing, have made possible the noninvasive detection of human brain activity. We work on quantum sensing with hot atomic vapors, in particular we study spin noise, which sets a fundamental limitation to the precision of such magnetic sensing measurements, and we explore the quantum foundations of spin-exchange collisions, which dominate the atomic spin dynamics.
Quantum biology is a new and interdisciplinary field synthesizing modern quantum information with the complexity of biological systems. The premise of quantum biology is that, like man-made quantum technology, there are biological systems that have realized a quantum advantage, meaning their function is fundamentally governed and supported by genuine quantum phenomena at the molecular level. In this respect, we have shown that spin-dependent biochemical reactions which regulate charge and spin transport in photosynthesis, and which underlie the avian magnetic compass mechanism, exhibit the full- blown effects of modern quantum information processing.
Quantum vision is a similarly new venture, aspiring to synthesize quantum optics with the physiology of human and animal vision. We perform experiments with human subjects, as well as in vitro experiments with animal photoreceptors. With regard to the former, we have developed a novel high precision pupillometry technique, accessing in a unique way the human brain and offering vast diagnostic information on retina and neurological diseases.
More information can be found here.
Polarization Spectroscopy Laboratory
Production of spin polarized hydrogen (SPH) atoms from molecular optical excitation
SPH has wide range of applications in spin physics and chemistry. We have pioneered the production of SPH at record pulsed densities, in excess of 1019/cm3 (over a millions times higher than conventional methods), from molecular photodissociation with circularly polarized light. This ultrahigh-density SPH has applications in the production of high-flux polarized particle beams using laser-plasma acceleration, for tests of polarized nuclear fusion, and as an ultrafast magnetometer. Methods for high production rates of spin-polarized atoms and molecules are being developed, from the IR-excitation of molecular beams, aiming at macroscopic production rates of at least 1020/s, whereas conventional methods, such as Stern-Gerlach spin-separation, are limited to about 1017/s. Application include NMR signal enhancement, and nuclear fusion yield enhancement.
Cavity-based signal-reversing chiral polarimetry
Polarimetry is a widely used method for the measurement of chirality in chemistry and biology, and is used in ultrasensitive magnetometry and parity nonconservation measurements in atomic physics. However, single-pass commercial polarimeters are limited to measurement of absolute optical rotation angles of about 5 μrad, and relative angles of about 10 nrad, due to imperfect subtraction of null measurements and spurious time-dependent birefringence. Our group is pioneering cavity-based signal-reversing polarimetery, which enhances the optical rotation signal by the number of cavity passes (typically 100-1000), while also suppressing birefringence and performing rapid signal reversals that improve null background subtraction. Together, these methods improve the absolute sensitivity of polarimetery by at least 3 orders of magnitude. We are pursuing applications of ultrasensitive polarimetry measurements, of thin chiral films at surfaces, and of parity-nonconservation in iodine atoms and HgH molecules.
For more information please see here.
Atomic Physics with Accelerators.
Atomic physics of few-electron processes in energetic ion-atom collisions are primarily investigated using high-resolution Auger electron spectroscopy. In 2013, with a grant supplied by the research program THALIS (2011-2015), a special beam line devoted to experimental atomic physics of ion-atom collisions has been setup at L45 at the 5.5MV tandem Van de Graaff accelerator of the Institute of Nuclear and Particle Physics at the NCSR Demokritos in Athens with the formation of the APAPES initiative specialized in high resolution Auger projectile electron spectroscopy. Measurements focus on a systematic isoelectronic investigation of K-Auger spectra emitted from collisions of pre-excited ions with gas targets using novel techniques. In 2020, new APAPES results, using pre-excited ion beams of C4+(1s2s 3S) in collisions with He and H2 targets, demonstrate for the first time, the breakdown of spin statistics in multielectron, multi-open-shell dynamical atomic systems.
For more information please see here.
