30th annual International Laser Physics Workshop
(July 18-22, 2022)

This year, our milestone thirtieth annual International Laser Physics Workshop (LPHYS'22) will be held from to , in the online format on Zoom.

According to most participants, last year, our LPHYS'21 conference on Zoom achieved substantial success. Three hundred twenty-six delegates from 26 countries over 11 time zones participated in the event.

This year, we will keep the Zoom conference as closely as possible to the standard in-person format of the previous years. We hope the cordial atmosphere that had always ruled at our annual meetings will continue.

This year, we will follow a simplified schedule for collecting conference fees. The fee amounts have been slashed. Please follow the Workshop Fees page. Each participant will receive Zoom links to all seminars and plenary sessions a few days before the event.

We want to remind you that our system is already available for abstract uploads (after pre-registration). The compiled LPHYS'22 Program will be available approximately a week before the event.

This year, IOP Publishing will implement new Conference Proceedings rules. Please review our Proceedings page.

Even though our workshops scheduled to take place in Lyon, France, have already been postponed three times in 2020, 2021, and 2022, we hope that our next Workshop will indeed take place there in 2023.

Please follow all our further announcements on matters related to the conference on this page.

LPHYS'22.  Steering Committee:

  • Photo

    Vanderlei S. Bagnato


    University of São Paulo, São Carlos, SP, Brazil
    Texas A&M University, College Station, TX, USA
  • Photo

    Joseph H. Eberly


    University of Rochester, Rochester, NY, USA
  • Photo

    Mikhail V. Fedorov


    A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, Russia
  • Photo

    Sergey A. Gonchukov


    National Research Nuclear University MEPhI, Moscow, Russia
  • Photo

    Sergei P. Kulik


    Lomonosov Moscow State University, Moscow, Russia
  • Photo

    Reinhard Kienberger


    Fakultät für Physik, E11, Technische Universität München, Garching, Bavaria, Germany
  • Photo

    Renbao Liu


    The Chinese University of Hong Kong, Hong Kong, China
     
  • Photo

    Vladimir A. Makarov


    Lomonosov Moscow State University, Moscow, Russia
  • Photo

    Dejan Milošević


    University of Sarajevo, Sarajevo, Bosnia and Herzegovina
  • Photo

    Gérard Mourou

    Nobel Prize Winner 
    École Polytechnique, Palaiseau, France
  • Photo

    Franco Nori


    Theoretical Quantum Physics Laboratory, Center for Quantum Computing, RIKEN, Japan
    University of Michigan, Ann Arbor, MI, USA
  • Photo

    Jian-Wei Pan


    University of Science and Technology of China, Hefei, Anhui, China
  • Photo

    Marlan O Scully


    Texas A&M University, Princeton, NJ, USA
    Baylor University, Waco, TX, USA
  • Photo

    Vladimir M. Shalaev


    Purdue University, West Lafayette, IN, USA
  • Photo

    Georgy V. Shlyapnikov


    Laboratoire de Physique Théorique et Modèles Statistiques, Orsay, France
  • Photo

    Toshiki Tajima


    University of California at Irvine, Irvine, CA, USA
  • Photo

    Valery M. Yermachenko


    National Research Nuclear University MEPhI, Moscow, Russia
  • Photo

    Vyacheslav I. Yukalov


    Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia
  • Photo

    Aleksey M. Zheltikov


    Lomonosov Moscow State University, Moscow, Russia

LPHYS'22.    Plenary Speakers:

  1. Quantifying Quantum Metrology: Noiseless Amplification, Precision Bounds For Open Systems, and Ghost Quantum Sensing

    • Photo

      Luiz Davidovich


      Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
      Institute for Quantum Science and Engineering, Texas A&M University, College Station, TX, USA
    Abstract:

    Quantum metrology is one of the basic pillars of quantum information, together with quantum computation, quantum simulation, and quantum communication. It concerns the estimation of parameters, for which lower bounds to the precision of estimation are derived through a rigorous theoretical framework, established by Cramér, Rao, and Fisher for classical systems and generalized to quantum physics by Helstrom and Holevo. This framework yields simple expressions for the precision when dealing with parameter-dependent unitary evolutions in closed systems. Open systems, on the other hand, require more sophisticated techniques [1-4]. This talk reviews recent results on closed and open systems: the analysis of an experiment on noiseless quantum amplification of mechanical oscillator motion [5,6], and the demonstration that, for open systems, a procedure analogous to quantum ghost imaging may increase the precision of estimation.

    [1] B. M. Escher, R. L. de Matos Filho, and L. Davidovic, Nature Physics 7, 406 (2011).
    [2] B. M. Escher, L. Davidovich, N. Zagury, and R. L. de Matos Filho, Phys. Rev. Lett. 109, 190404 (2012).
    [3] C. L. Latune, B. M. Escher, R. L. de Matos Filho, and L. Davidovich, Phys. Rev. A 88, 042112 (2013).
    [4] J. Wang, L. Davidovich, and G. S. Agarwal, Phys. Rev. Research 2, 033389 (2020).
    [5] S. C. Burd, R. Srinivas, J. J. Bollinger, A. C. Wilson, D. J. Wineland, D. Leibfried, D. H. Slichter, and D. T. C. Allcock, Science 364, 1163 (2019).
    [6] G. S. Agarwal and L. Davidovich, Phys. Rev. Research 4, L012014 (2022).

  2. From Multi-Photon Entanglement to Quantum Computational Advantage

    • Photo

      Jian-Wei Pan


      University of Science and Technology of China, Hefei, Anhui, China
    Abstract:

    Photons, the fast flying qubits which can be controlled with high precision using linear optics and have weak interaction with environment, are the natural candidate for quantum communications. By developing a quantum science satellite Micius and exploiting the negligible decoherence and photon loss in the out space, practically secure quantum cryptography, entanglement distribution, and quantum teleportation have been achieved over thousand kilometer scale, laying the foundation for future global quantum internet. Surprisingly, despite the extremely weak optical nonlinearity at single-photon level, an effective interaction between independent indistinguishable photons can be effectively induced by a multi-photon interferometry, which allowed the first creation of multi-particle entanglement and test of Einstein’s local realism in the most extreme way. By developing high-performance quantum light sources, the multi-photon interference has been scaled up to implement boson sampling with up to 76 photons out of a 100-mode interferometer, which yields a Hilbert state space dimension of 1030 and a rate that is 1014 faster than using the state-of-the-art simulation strategy on supercomputers. Such a demonstration of quantum computational advantage is a much-anticipated milestone for quantum computing. The special-purpose photonic platform will be further used to investigate practical applications linked to the Gaussian boson sampling, such as graph optimization and quantum machine learning.

  3. Quantum Optics with Giant Atoms: Decoherence-Free Interaction between Giant Atoms in Waveguide Quantum Electrodynamics

    • Photo

      Franco Nori


      Theoretical Quantum Physics Laboratory, Center for Quantum Computing, RIKEN, Japan
      University of Michigan, Ann Arbor, MI, USA
    Abstract:

    In quantum optics, atoms are usually approximated as point-like compared to the wavelength of the light they interact with. However, recent advances in experiments with artificial atoms built from superconducting circuits have shown that this assumption can be violated. Instead, these artificial atoms can couple to an electromagnetic field in a waveguide at multiple points, which are spaced wavelength distances apart. Such systems are called giant atoms. They have attracted increasing interest in the past few years (e.g., see the review in [1]), in particular because it turns out that the interference effects due to the multiple coupling points allow giant atoms to interact with each other through the waveguide without losing energy into the waveguide (theory in [2] and experiments in [3]). This talk will review some of these developments. Finally, we will also show how a giant atom coupled to a waveguide with varying impedance can give rise to chiral bound states [4].

    [1] A.F. Kockum, Quantum optics with giant atoms -- the first five years, https://arxiv.org/abs/1912.13012
    [2] A.F. Kockum, G. Johansson, F. Nori, Phys. Rev. Lett. 120, 140404 (2018)
    [3] B. Kannan, M. J. Ruckriegel, D. L. Campbell, A. F. Kockum, J. Braumüller, D. K. Kim, M. Kjaergaard, P. Krantz, A. Melville, B. M. Niedzielski, A. Vepsäläinen, R. Winik, J. L. Yoder, F. Nori, T. P. Orlando, S. Gustavsson, and W. D. Oliver, Nature 583, pp. 775 (2020)
    [4] X. Wang, T. Liu, A.F. Kockum, H.R. Li, F. Nori, Phys. Rev. Lett. 126, 043602 (2021). [PDF]

  4. Measuring the timing of the photoelectric effect

    • Photo

      Reinhard Kienberger


      Fakultät für Physik, E11, Technische Universität München, Garching, Bavaria, Germany
    Abstract:

    The generation of single isolated attosecond pulses in the extreme ultraviolet (XUV) together with fully synchronized few-cycle infrared (IR) laser pulses allowed to trace electronic processes on the attosecond timescale. A pump/probe technique, “attosecond streaking” [1], was used to investigate electron dynamics on surfaces and layered systems with unprecedented resolution. Photoelectrons generated by laser based attosecond extreme ultraviolet pulses (XUV), are exposed to a dressing electric field from well synchronized laser pulses. The energy shift experienced by the photoelectrons by the dressing field is dependent on the delay between the XUV pulse and the dressing field and makes it possible to measure the respective delay in photoemission between electrons of different type (core electrons vs. conduction band electrons). The information gained in such experiments on tungsten [2] triggered many theoretical activities leading to different explanations on the physical reason of the delay. Attosecond streaking experiments have been performed on different solids [3,4], layered structures and liquids, resulting in different delays – also depending on the excitation photon energy. These measurements lead to a stepwise increase of the understanding of different physical effects contributing to the timing of photoemission. In this presentation, an overview on the different physical contributions to attosecond time delays in photoemission will be given. The “absolute” time delay, i.e. the delay between the instant of ionization and the emission of a photoelectron will be discussed and new measurements will be presented.

    [1] R. Kienberger et al., Nature 427, 817 (2004)
    [2] A. Cavalieri et al., Nature 449, 1029 (2009)
    [3] S. Neppl et al., Nature 517, 342 (2015)
    [4] Ossiander et al., Nature 561, pages374 (2018)

  5. Massive matter-wave interferometers on the atom chip with nano-diamonds: a roadmap

    • Photo

      Ron Folman


      Physics Department, Ben-Gurion University of the Negev, Be'er Sheva, Israel
    Abstract:

    Matter-wave interferometry provides an excellent tool for fundamental studies as well as technological applications. Looking to the future, a spatial superposition of massive objects has long been sought after due to the potential for new insight into the foundations of quantum mechanics (QM), the interface of QM and gravity, and as a tool for testing exotic theories. In our group, several interferometry experiments have been conducted with a BEC on an atom chip. I will briefly present realized interferometric schemes based on Stern-Gerlach interferometry (SGI), and mainly focus on plans to use this unique SGI to put a nano diamond in a state of spatial superposition.

  6. Opportunities for quantum biosensing with fluorescent diamond and phosphor nanoparticles

    Abstract:

    Fluorescent nanoparticles can probe biological processes on the nanoscale, sometimes with the potential for quantum-enhanced sensing. I will give a brief overview of the field with emphasis on opportunities for hybrid integration of diamond and upconversion phosphor particles. In particular, I will discuss some experimental examples of using both types of particles as biological probes. I will also discuss opportunities to use the quantum nature of some of the fluorescent particles to improve sensitivity.

  7. Absolute quantum advantage in imaging: quantum correlations allow imaging of otherwise unobservable biological structures

    • Photo

      Warwick P. Bowen


      The University of Queensland, Brisbane, Australia
    Abstract:

    It has been recognised since the 1980s that quantum light sources have the potential to improve the performance of microscopes, enhancing the information that can be extracted from biological systems at fixed photon budget [1]. Indeed, today state-of-the-art microscopes use intense lasers that can severely disturb biological processes, function and viability. This introduces hard limits on performance that only quantum photon correlations can overcome [2]. As such, the development of photodamage evading microscopes is widely considered as a key milestone in quantum technology roadmaps (e.g. [3]).

    In this talk I will report work which demonstrates absolute quantum advantage in biological imaging [3]. We show that quantum correlations enable signal-to-noise beyond the photodamage-free capacity of conventional microscopy. Broadly, this represents the first demonstration that quantum correlations can allow sensing beyond the limits introduced by optical intrusion upon the measurement process. We achieve this in a coherent Raman microscope, which we use to image molecular bonds within a cell with both quantum-enhanced contrast and sub-wavelength resolution. This allows imaging of biological structures that are inaccessible using classical light. Coherent Raman microscopes allow highly selective biomolecular finger-printing in unlabelled specimens, but photodamage is a major roadblock for many applications. By showing that this roadblock can be overcome, our work provides a path towards order-of-magnitude improvements in both sensitivity and imaging speed.

    Quantum-enhanced stimulated Raman microscope
    Fig. 1 Quantum-enhanced stimulated Raman microscope. Top: microscope design. Bottom: comparison of quantum-enhanced and conventional images.

    [1] Slusher, R. E. Quantum optics in the ’80s. 1990. Opt. Photon. News 1, 27–30.
    [2] Taylor, M. A. & Bowen, W. P. 2016. Quantum metrology and its application in biology. Phys. Rep. 615, 1–59.
    [3] Casacio, C. A. et al., Quantum-enhanced nonlinear microscopy. 2021. Nature 594 201–206.

  8. Efficient sampling from the quantum state space

    Abstract:

    A random sample of quantum states with specific properties is useful for various applications. Since the quantum state space has highly complicated boundaries in high dimension due to the positivity constraint, it is challenging to incorporate the specific properties into the sampling algorithm. The Sequentially Constraint Monte Carlo (SCMC) algorithm is a powerful method for sampling quantum states in accordance with any desired properties that can be described by inequalities. For illustration, we apply this method to the sampling of quantum states with bound entanglement, high-dimensional quantum states with a desired target distribution, and uniformly distributed quantum states in regions bounded by values of the problem-specific target distribution. These examples demonstrate that the SCMC sampler is efficient and reliable; perhaps, it also overcomes the curse of dimensionality. (Based on arXiv:2109.14215)

  9. Capitalizing on Schrödinger

    Abstract:

    The superposition principle is a cornerstone of quantum mechanics and results from the linearity of the Schrödinger equation. In this talk we motivate the non-linear wave equation of classical statistical mechanics as well as the linear Schrödinger equation of quantum mechanics from a mathematical identity. Moreover, the linearity is crucial for the use of matter wave interferometers as sensors for rotation and acceleration. We show that the phase in a Kasevich-Chu atom interferometer measures the commutator of two unitary time evolutions and thus the acceleration. In addition, we report the observation of the Kennard phase using water waves and the realization of a Kennard interferometer with a scaling superior to the Kasevich-Chu interferometer.

  10. Programmable Quantum Simulation with Trapped Ions

    Abstract:

    Trapped ions provide a prominent platform to implement quantum information processing tasks, including quantum computing and quantum simulation with tens of qubits. The ability to precisely engineer many-body Hamiltonians and to perform single-site and single-shot readouts have seen trapped ions evolve into a new generation of programmable quantum simulators, which combine a certain amount of programmability with scalability to large particle numbers. In this talk we first introduce the core idea of collective phonon modes that allow to generate controlled entanglement in a chain of ultracold ions. Then we move on to discuss recent results obtained on a trapped ion platform with up to fifty qubits/spins, with the goal to develop and demonstrate quantum protocols, addressing questions from the fundamental to the practical. Examples include variational ground state engineering, measurement protocols revealing the entanglement structure of the many-body wavefunction, and implementing 'optimal' quantum metrology with variational quantum circuits.

  11. 100 years of complementarity

    • Photo

      János A. Bergou


      Department of Physics and Astronomy, Hunter College of the City University of New York, New York, NY, USA
      Graduate Center of the City University of New York, New York, NY, USA
    Abstract:

    Einstein in 1905, in his explanation of the photoelectric effect, postulated that light, the quintessential wave, had to possess particle-like properties. In the course of 1923-24, de Broglie, analyzing electron scattering from metal surfaces, postulated that electrons, the quintessential particles, must possess wave-like properties. In 1928, Bohr made the first attempt to reconcile the two viewpoints and introduced the concept of complementarity (or, in a more restricted sense, wave-particle duality), and thus the by now nearly 100 years history of complementarity has started. We will overview the history [1-5] and present recent results [6-12], highlighting that to complete complementarity, beside wave and particle features (which have classical counterparts), a third, truly quantum, reality, entanglement, must be included.

    [1] D. M. Greenberger and A. Yasin, Phys. Lett. A128, 391 (1988).
    [2] B.-G. Englert, Phys. Rev. Lett. 77, 2154 (1996).
    [3] B.-G. Englert and J. A. Bergou, Opt. Commun. 179, 337 (2000).
    [4] M. Jakob and J. A. Bergou, Opt. Commun. 283, 827 (2010) [also as arxiv:0302075].
    [5] M. Jakob and J. A. Bergou, Phys. Rev. A 76, 052107(2007).
    [6] T. Baumgratz, M. Cramer, and M. B. Plenio, Phys. Rev. Lett. 113, 140401 (2014).
    [7] E. Bagan, J. A. Bergou, S. S. Cottrell, and M. Hillery, Phys. Rev.Lett. 116, 160406 (2016).
    [8] E. Bagan, J. Calsamiglia, J. A. Bergou, and M. Hillery, Phys. Rev.Lett. 120, 050402 (2016).
    [9] E. Bagan, J. Calsamiglia, J. A. Bergou, and M. Hillery, Journal of Physics A: Math. Theor. 51, 414015 (2018).
    [10] E. Bagan, J. A. Bergou, and M. Hillery, Phys. Rev. A 102, 022224 (2020).
    [11] X. Lü, Phys. Rev. A 102, 02201 (2020).
    [12] X. Lü, Phys. Lett. A397, 127259 (2021).

  12. Compact widely tunable room temperature Terahertz Molecular Lasers from 250 GHz to 4.6 THz

    • Photo

      Federico Capasso


      John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
    Abstract:

    Quantum cascade lasers (QCLs) are the dominant source in the mid-IR and have found a wide range of applications in chemical sensing, trace gas monitoring, biomedical and spectroscopy. However, their performance falls short in the Terahertz gap. Other THz lasers, such as molecular lasers, have similar limitations in addition to a large footprint. We have realized a compact, room temperature, widely frequency-tunable, bright THz QCL pumped molecular laser (QPML) based on rotational population inversion. By identifying the essential parameters that determine the suitability of a molecule for a terahertz laser, almost any rotational transition of almost any molecular gas can be made to lase. Using Nitrous oxide (N2O) as the gain medium we demonstrated tunability over 37 lines spanning 0.251 to 0.955 terahertz, each with kilohertz linewidths [1]. We have recently achieved lasing in methyl fluoride (CH3F) QPML, where we showed laser operation between 250 GHz and 1.255 THz – line tunable over more than 1 THz [2]. We additionally measured the emission frequencies of more than 70 individual laser lines between 300 GHz and 755 GHz. The CH3F QPML was shown to exhibit a low lasing threshold (reduced by a factor 7 compared to our previous work with nitrous oxide), thus making methyl fluoride a promising gain medium for many QPML applications. Finally, we have recently reported explored the potential of the ammonia QPMLs to produce powerful, broadly tunable terahertz frequency lasing on rotational and pure inversion transitions [3]. After theoretically predicting possible laser frequencies, pump thresholds, and efficiencies, we experimentally demonstrated unprecedented tunability — from 0.763 to 4.459 THz — by pumping Q- and R-branch infrared transitions. with widely tunable quantum cascade lasers. We additionally demonstrated two types of multi-line lasing: simultaneous pure inversion and rotation– inversion transitions from the same pumped rotational state and cascaded lasing involving transitions below the pumped rotational state. We report single frequency power levels as great as 0.45 mW from a low volume laser cavity.

    [1] P. Chevalier et al. Science 366, 856 (2019)
    [2] A. Amirzhan et al. APL Photonics, 7, 016107 (2022)
    [3] P. Chevalier et al. Applied Physics Letters, 120, 8, 081108 (2022)

LPHYS'22.  Advisory & Program Committee:

LPHYS'22.    Deadlines:

Event Deadline Days left
Online pre-registration (if you want to present a talk/poster) July 15, 2022 -
Online pre-registration (if you don't want to present a talk/poster) July 23, 2022 -
Submitting an abstract of your presentation July 15, 2022 -
Submitting a manuscript for conference proceedings publishing January 15, 2023 -

LPHYS'22.  Proceedings:

Proceedings of the 30th annual International Laser Physics Workshop (LPHYS'22, , July 18-22, 2022) have been published in Journal of Physics: Conference Series, vol. 2494 (2023). To read all contributed papers please visit https://iopscience.iop.org/issue/1742-6596/2494/1.

LPHYS'22. Technical Information:

First, please register online as a participant. When registering as a new participant for the first time, your Workshop Personal Page will be created at this time. Just proceed to the 'Register for Workshop' in the navigation bar on the left. If you participated in one or more of our previous workshops, your saved Personal Page would be retrieved from our system at registration. At this time, if needed, you can update and edit your personal information from earlier years.

After registration, please proceed to the 'Workshop Fees' page by first selecting the 'For Participants' option. Without paying the fee, the system will not allow you to submit the abstract of your presentation and provide access to the online sessions.

To submit your abstract(s), please go to your Participant's Personal Page and select the 'Abstract(s)' option in the navigation bar on the left. The system will bring you to the 'Abstracts for LPHYS'21' page, where you can prepare, upload, and edit your abstract(s) to be included in the LPHYS'22 Program after a proper peer review. On that page, you can find many important details and instructions for your submission.

Upon accepting your abstract, the heading of your talk will appear on your Seminar page (1 through 9) with the assigned date and time. Your seminar co-chairs will do all scheduling by setting dates and times for each talk. Please address all matters related to scheduling to your seminar co-chairs.

In the unlikely case that your abstract is not accepted and you had already paid your registration fee, we will refund the full amount of your payment to the account from which this payment had been made.

We will open nine uninterrupted Zoom sessions, one for each seminar, every day for the conference duration. The tenth Zoom session will be arranged for daily plenary sessions as the first meetings of the day. All seminar meetings will follow the plenary session. The format of each seminar session will be kept as closely as possible to the in-person offline format. It comes in response to the need to accommodate the talks from as many world time zones as possible. Two short "coffee breaks" will be provided each meeting day.

Zoom will use the time in Paris, France (GMT+2) as a baseline time for all LPHYS'22 sessions. The daily meetings will start each day with two or three 45 min plenary sessions followed by the individual seminar sessions. The plenary sessions will begin each day at 14:00 (2:00 pm), Paris time. Please determine the beginning time in your time zone and adjust your conference schedule accordingly.

All registered participants who paid the fee will receive the Zoom access links on their Personal Pages, nine seminar links, plus one plenary session link.

An important notice. Before starting your Zoom participation, please check the following.

  • Your Internet connection traffic speed. The higher speed, the better.
  • After entering a Zoom session, the microphone and camera are ON.
  • Enough light illuminates your face before your camera.

If you have any questions or issues, please contact your seminar co-chairs for assistance.