PICC News & Events

4.-6. October 2016: Project Meeting “Quantum Crystals of Matter and Light”

“Quantum Crystals of Matter and Light”, Project Workshop
Saarbruecken, October 4th-6th, Campus E26, Room E04.


Each talk: 30 Minutes + 10 minutes discussion

Tuesday October 4th
Start at 15:15 Welcome - Juergen Eschner and Giovanna Morigi
15:30 Lorenz Hruby “Metastable many-body states in a cavity”
16:00 Discussion
16:10 Igor Mekhov “Competition between weak quantum measurement and many-body dynamics”
16:40 Discussion
16:50 Coffee Break
17:15 Andreas Buchheit “Commensurate-Incommensurate Transition in presence of cavity backaction”
17:45 Discussion
18:00 End of Session
19:00 Dinner - Pizzeria Italia

Wednesday October 5th
9:00 Hannes Goethe ““Emission from a side-pumped atom-cavity system”
9:30 Discussion
9:40 Valentin Torggler “Optimization with ultracold atoms in a multimode optical resonator”
10:10 Discussion
10:20 Coffee Break
10:45 Tim Keller “Thermodynamics of photon-mediated selforganization in multimode cavities”
11:15 Discussion
11:25 Simon Jäger “Semiclassical theory of synchronization-induced supercooling”
11:55 Discussion
12:30 Lunch / Mensa
14:30 Lab Tour, J. Eschner,
Then free afternoon (Project meeting: Donner, Eschner, Morigi, Ritsch)
19:00 Dinner at Stiefel

Thursday October 6th
9:00 Andrea Morales “Supersolid formation in a quantum gas breaking continuous translational symmetry”
9:30 Discussion
9:40 Rebecca Kraus “(Few-Body) Localization in presence of cavity backaction”
10:10 Discussion
10:20 Coffee Break
10:45 Benjamin Bogner “Cavity-induced quantum phases of ultracold atoms in commensurate potentials”
11:15 Discussion
11:25 Farokh Mivehvar “Topological Fermionic Superradiant Phase in Transversely Pumped Cavities”
11:55 Concluding Discussion
12:30 Lunch /Mensa
14:00 Departure

PICC Final Review, Brussel January 14th, 2014.

PICC Final Review is taking place in Brussel on January 14th, 2014.

International School of Physics “Enrico Fermi” on “Ion Traps for Tomorrow’s Applications”

Varenna (Italy)  July 22 2013 – July 30 2013

International School of Physics “Enrico Fermi” on “Ion Traps for Tomorrow’s Applications”
Varenna (Italy)  July 22 2013 – July 30 2013

Martina Knoop - Université de Provence, Marseille (France)
Irene Marzoli - Università di Camerino (Italy)
Giovanna Morigi - Universität des Saarlandes (Germany)


2nd Newsletter online

Second PICC newsletter presents achievements and the consortium

The PICC consortium proudly presents the 2nd edition of the PICC newsletter. It contains the achievements of yet another successful project year and presents the theoretical partners of the project.

The 3rd newsletter will be published at the end of the project.

Download the newsletter as PDF file.

Nobel Prize in physics 2012 for trapped ions and photons

Award goes jointly to Serge Haroche and David Wineland

Serge Haroche and David Wineland won the Nobel Prize in Physics 2012 for their “for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems”.

For more information please have a look at the Nobel Prize webpage.

New article in Physical Review Letters

Structural Transitions of Ion Strings in Quantum Potentials

Cecilia Cormick and Giovanna Morigi
Phys. Rev. Lett. 109, 053003 (2012).

We analyze the stability and dynamics of an ion chain confined inside a high-finesse optical resonator. When the dipolar transition of the ions strongly couples to one cavity mode, the mechanical effects of light modify the chain properties close to a structural transition. We focus on the linear chain close to the zigzag instability and show that linear and zigzag arrays are bistable for certain strengths of the laser pumping the cavity. For these regimes the chain is cooled into one of the configurations by cavity-enhanced photon scattering. The excitations of these structures mix photonic and vibrational fluctuations, which can be entangled at steady state. These features are signaled by Fano-like resonances in the spectrum of light at the cavity output.

2nd Review Meeting

The internal 2nd Scientific Review Meeting takes place at July 25 in Saarbrücken

Date and time: July 25, 2012 8:30 - 17:15

PICC researcher honored

Martin B. Plenio of UULM receives Max-Born Medal and Prize

Martin B. Plenio, of the University of Ulm, researcher in the PICC project, receives the 2012 Max-Born Medal and Prize jointly awarded by the German Physical Society and the British Institute of Physics for his ground-breaking contributions to the theory of entanglement and its applications which have stimulated and guided the development of practical realisations of quantum information processing and the control of quantum dynamics.

Congratulations from the PICC consortium to this outstanding award!

More information can be found at:

Ulm University Website
IOP Website

1st Newsletter published

First newsletter of PICC with information on the project and its people.

The PICC consortium is pleased to present the first project newsletter with interesting information on the project and its people. More newsletters will follow in the course of the project.

Download the newsletter as PDF file.

Open House at USIEG

Partner USIEG opened its laboratory to science-loving children, gave tours
through the lab and realised hands-on experiments.

July 10, 2011 at Universität Siegen, Germany

Partner USIEG opened its laboratory to science-loving children, gave tours
through the lab and realized hands-on experiments. This “open house” took
place with a famous German children’s series, “Sendung mit der Maus”, which
is hailed for its ability to convey e.g. academic, technological or
scientific information to children.

Lots of the visitors were pupils from local schools come to pester the
researchers with questions. They learned, for instance, how vibrations turn
to waves or how things can float. Children, but adults as well, could test,
experiment and play and experienced how single atoms are trapped, cooled and
controlled with lasers.

“It was a true success”, stated Dr. Michael Johanning from USIEG.

More information on the article of the “Türen auf” program on the website of the WDR broadcast station (in German).

New article in Physical Review Letters

Optimal Control Technique for Many-Body Quantum Dynamics

P. Doria, T. Calarco, and S. Montangero

Phys. Rev. Lett. 106, 190501 (2011).


We present an efficient strategy for controlling a vast range of nonintegrable quantum many-body one-dimensional systems that can be merged with state-of-the-art tensor network simulation methods such as the density matrix renormalization group. To demonstrate its potential, we employ it to solve a major issue in current optical-lattice physics with ultracold atoms: we show how to reduce by about 2 orders of magnitude the time needed to bring a superfluid gas into a Mott insulator state, while suppressing defects by more than 1 order of magnitude as compared to current experiments [T. Stöferle et al., Phys. Rev. Lett. 92, 130403 (2004)]. Finally, we show that the optimal pulse is robust against atom number fluctuations.

New article in New Journal of Physics

Hawking radiation on an ion ring in the quantum regime

B. Horstmann, R. Schützhold, B. Reznik, S. Fagnocchi, J. I. Cirac

New J. Phys.13, 045008 (2011).

This paper discusses a recent proposal for the simulation of acoustic black holes with ions (Horstmann et al 2010 Phys. Rev. Lett. 104 250403). Ions are rotating on a ring with an inhomogeneous but stationary velocity profile. Phonons cannot leave a region in which the ion velocity exceeds the group velocity of the phonons, because light cannot escape from a black hole. The system is described by a discrete field theory with a nonlinear dispersion relation. Hawking radiation is emitted by this acoustic black hole, generating entanglement between the inside and the outside of the black hole. We study schemes for detecting the Hawking effect in this setup.

New article in New Journal of Physics

Enhancement of laser cooling by the use of magnetic gradients

Andreas Albrecht, Alex Retzker, Christof Wunderlich, Martin B. Plenio
New Journal of Physics. 13, 033009 (2011).

We present a laser cooling scheme for trapped ions and atoms using a combination of laser couplings and a magnetic gradient field. In a Schrieffer–Wolff transformed picture, this setup cancels the carrier and blue sideband terms completely (up to first order in the Lamb–Dicke parameter), resulting in an improved cooling behaviour compared to standard cooling schemes in the Lamb–Dicke regime (e.g. sideband cooling) and allowing cooling to the vibrational ground state. A condition for optimal cooling rates is presented and the cooling behaviour for different Lamb–Dicke parameters and spontaneous decay rates is discussed. Cooling rates of one order of magnitude less than the trapping frequency are achieved using the new cooling method. Furthermore, the scheme exhibits fast rates and low final populations, even for significant deviations from the optimal parameters, and provides good cooling rates also in the multi-particle case.

QIPC 2011 - Conference at ETH Zurich in September

ETH Zurich, September 5 - 9, 2011.

The conference program will cover a broad range of topics: in

  • Quantum Information and Quantum Communication
  • Physical Realizations for Information Technology e.g. Photons, Single Atoms, Ions, Molecules, Nuclear and Electron Spins, Superconducting Circuits, Micro- and Nano-Mechanics, Hybrid Quantum Systems
  • Cavity QED, Optical Lattices, Quantum Memories, Foundations of Quantum Information, and Many-Body Systems

Read more at the website of the QIPC 2011 Conference

IOTA Scientific Kick-off meeting

Internationales Wissenschaftsforum, Heidelberg/Germany March 23-25, 2011

Read more at the IOTA website

New article in Nature Photonics

Optical Trapping of an Ion

Ch. Schneider,  M. Enderlein, T .Huber and T. Schaetz

Nature Photonics 4, 772–775 (2010)


New article in Physical Review Letters

Quantum zigzag transition in ion chains

E. Shimshoni, G. Morigi, S. Fishman

Phys. Rev. Lett 106, 010401 (2011)

New article in New Journal of Physics

Spontaneous nucleation of structural defects in inhomogeneous ion chains

Gabriele De Chiara, Adolfo del Campo, Giovanna Morigi, Martin B. Plenio and Alex Retzker.
New Journal of Physics 12, 115003 (2010).

Structural defects in ion crystals can be formed during a linear quench of the transverse trapping frequency across the mechanical instability from a linear chain to a zigzag structure. The density of defects after the sweep can be conveniently described by the Kibble–Zurek mechanism (KZM). In particular, the number of kinks in the zigzag ordering can be derived from a time-dependent Ginzburg–Landau equation for the order parameter, here the zigzag transverse size, under the assumption that the ions are continuously laser cooled. In a linear Paul trap, the transition becomes inhomogeneous, since the charge density is larger in the center and more rarefied at the edges. During the linear quench, the mechanical instability is first crossed in the center of the chain, and a front, at which the mechanical instability is crossed during the quench, is identified that propagates along the chain from the center to the edges. If the velocity of this front is smaller than the sound velocity, the dynamics become adiabatic even in the thermodynamic limit and no defect is produced. Otherwise, the nucleation of kinks is reduced with respect to the case in which the charges are homogeneously distributed, leading to a new scaling of the density of kinks with the quenching rate. The analytical predictions are verified numerically by integrating the Langevin equations of motion of the ions, in the presence of a time-dependent transverse confinement. We argue that the non-equilibrium dynamics of an ion chain in a Paul trap constitutes an ideal scenario to test the inhomogeneous extension of the KZM, which lacks experimental evidence to date.

PICC Kick-Off Meeting

The kick-off meeting has taken place on 16th July 2010 in Brussels

Download the agenda of the kick-off meeting as .pdf-file.

PICC website online