Quantum Fluids

Welcome to the Quantum-Fluid group at the Physikalisches Institut of the University of Heidelberg! We are a new research group exploring the behaviour of quantum fluids using ultracold assemblies of atoms.

On this website, you will find more information on our team, our research, as well as the opportunities to join us! If you have any further question or want to join, do not hesitate to contact us.

We are part of the Cluster of Excellence STRUCTURES. We are also members of the SFB ISOQUANT Collaborative Research Center. Besides developing our activities at the Physikalisches Institut, we are involved in developing new directions within the upcoming institute EINC. You can learn more on this rich and exciting environment by clicking on the links above.



01/05/2024: Julius joins us as a new Hiwi!

Julius, master student at Heidelberg University, is joining the group as a new Hiwi. Hopefully he will help us improve on a safe operation of our devices in the lab ;P Welcome Julius!



22/04/2024: Lenny joins us again for his master project!

After a few months in South Korea and a very successful oral master's exam, Lenny has re-joined the group at the beginning of the summer semester, now for his master-thesis project. Lenny will first be working on our high resolution imaging and designing a proper scheme to detect high densities and correlations. Welcome again Lenny, we are very happy to have you back!



February -March 2024: Here a little catch-up of the news with many changes!


03/2024: Shuwei finishes his postdoc time with us to start a job in industry

It is with deep emotion that we see Shuwei leaving the group after 2.5 years of postdoc with us. It has been a fantastic adventure and a pleasure to start the group and build the experiment with you. We are infinitely grateful for your time, dedication, and always insightful comments, as well as for the fun time. We wish you the best of luck in your new position and hope you will visit us often from Stuttgart :)



03/2024: Sarah leaves the group for new adventures abroad!

After a few additional months as a Hiwi in the group, Sarah leaves the group and Heidelberg to explore more of the ultracold world worldwide. Sarah, we thank you for the great time, and we wish you all the best first for your stay in the US and for the following. Looking forward to meeting you soon again and speaking French ;)



03/2024: Jonah defends his bachelor thesis!

After many overnight measurements and analysis, Jonah very successfully defended his bachelor thesis on the phase stabilization of our accordion lattice. Jonah thank you very much for your work and all the best for your long trip and for your future studies abroad.



02/2024: Lea joins us for her bachelor project!

End of February, Lea joined us to work on her bachelor thesis. She will be working on some numerical simulations of our dipolar quantum gases.



01/2024: PhD and PostDoc openings!

For an exciting start in this new year, we are pleased to announce two open positions - 1 PhD & 1 postdoc - in our ultracold dysprosium experiment, see the flyer here and details here!



14/12/2023: Sarah submitted her master thesis!

In early December, Sarah finished her Master's thesis and submitted her manuscript, she is only two reviews away from becoming a Master of Science ;) Congratulations Sarah! And, after this writing period, we are happy to welcome you as a Hiwi in the group :)



October-November 2023: Here a little catch-up of the news!


11/2023: Nele starts as a new Hiwi in the YD lab!

Beginning of November, Nele, master student at Heidelberg University, joined us to work as a Hiwi in the Dy lab. Welcome Nele!



10/2023: Christian starts his master project on the YD lab!

In the end of October, Christian, long-time member of the QF group ;), successfully passed his Master oral exam and started his Master project with us. Welcome again Christian :)!



10/2023: Our ANR-DFG bilateral project DISQuTT has been granted!

End of October, we heard the great news that the bilateral collaborative project that we submitted with our collaborator in Villetaneuse, Laurent Vernac and Bruno Laburthe Tolra, has just been granted. This project, entitled "DISQuTT: Dipolar Interacting Systems: Quantum Thermalization and Turbulence" is funded by the ANR and the DFG and will allow us to develop great synergies between our YD lab and the Chromium experiment in Villetaneuse.



10/2023: Jonah joins the YD lab for his bachelor project!

In mid-October, Jonah joined us to work on his bachelor thesis. He will be working on a central fringe stabilization scheme for our accordion lattice setup. Welcome Jonah!



18/09/2023: Britta and Maurice defended their Bachelor thesis!

Our two fantastic bachelor students of this summer semester successfully defended their thesis this Monday, in the morning and afternoon respectively! Britta built and characterised our absorption imaging setup and Maurice worked on our magnetic field characterisation and toward a potential spin manipulation in our Dy experiment. Both works were tremendous, all our congratulations to both of you! We wish you a lot of joy and success in your future studies!



06/09/2023: Our paper on the (dis)continuity of the compressibility and speeds of sound in a supersolid is in PRR!

Our collaborative work with Blair Blakie and Danny Bailly (New Zeeland) and Francesca Ferlaino (Austria) in which we theoretically investigate the low-energy response of an elongated quantum gas of magnetic atoms at the transition between superfluid and supersolid has been published as a n article in Physical Review Research. We focus on a regime where the superfluid-supersolid transition is continuous and characterise the discontinuity occurring in the speeds of sound and compressibility. To learn more, have a look here!



04/09/2023: Last days of Charles’ Internship

This week was Charles' last visit as a Master Intern in the Dy Lab before his final defense this Wednesday. Charles, it was super cool to have you with us for these few months. Thank you for all your dedication to the accordion setup and in general to our apparatus and the physics of it. Thanks for nourishing a great team spirit, especially with a great French touch. Charles is going to join the group of G. Modugno in Pisa to continue as a PhD student. We wish you good luck and hope to stay in touch!



23/08/2023: Fabrizio joins us for a one-month internship

Fabrizio Klassen, master student at Heidelberg University, joins the Dy-Lab team for a one-month internship before leaving for an exchange semester in Japan. During this time, Fabrizio will work on improving the data analysis program and GUI that we use daily in the lab!



18/08/2023: Our first Dy-Lab paper is published in PRA

Our paper reporting on our apparatus source design and its performance has been published as a research article in Physical Review A this month! If you want to know how to make a 2D MOT of dysprosium and directly load a 3D MOT working on a narrow line from it with high efficiency, give it a read! You can find it here!



24/07/2023: Felix successfully defended his bachelor thesis

At the end of July, Felix successfully completed his bachelor's degree by defending his thesis, which aimed to better understand the imaging and fitting process for the lithium cloud in our Li-Cs mixture experiment. He was the first student to work on this experiment under the main supervision of Lauriane :) Thank you very much for your work and your trust, Felix. You have all my congratulations for your excellent and successful work. I genuinely learned a lot and I hope we can work together again.



17/07/2023: Wyatt joins us as a theory postdoc!

In mid-July, Wyatt Kirkby joined us in the framework of a two-year exploratory project funded by STRUCTURES. He will strengthen our collaboration with Thomas Gasenzer's group by being a joint member of both groups and working towards an understanding of the behavior of dipolar gases on both the static and dynamic sides using a combination of numerical techniques. Wyatt completed his Ph.D. in Canada under the supervision of Duncan O'Dell and graduated in 2022. Before joining us, Wyatt spent a year in the group of Russel Bisset in Innsbruck. Welcome Wyatt! We look forward to understanding new physics with you!



07/2023: Thibault finishes his internship, Joschka joins again!

At the beginning of July, Thibault finished his time with us as a Master Intern and went back to France. Shortly before that, Joschka came back from the USA and joined us for at least three months! To celebrate, we decided to have our first group bowling event... It was great to have the winner of the game with us for a few months! We thank you very much for what you bring during this time and we are looking forward to testing the DMD with the atoms soon. It was very impressive to see how fast and accurate you were on both the experimental and theoretical side, I look forward to continuing the exchange with you and it would be great to welcome you again in the future if there is an opportunity! Joschka, it is nice to have you back, and for sure the next three months will be a lot of fun, and maybe more ;) Let's see what the future has in store for us all!



06/2023: Our paper on the (dis)continuity of the compressibility and speeds of sound in a supersolid is on Arxiv!

Our paper entitled “Compressibility and speeds of sound across the superfluid to supersolid phase transition of an elongated dipolar gas” is now available. In this work developed in collaboration with Blair Blakie and Danny Bailly (New Zeeland) and Francesca Ferlaino (Austria), we theoretically explore the changes in the excitation spectrum and compressibility of an elongated quantum gas of magnetic atoms at the transition between superfluid and super solid. In the regime where this transition occurs continuously, we observe a discontinuous behaviour of these characteristic quantities. To learn more, have a look here!



05/2023: Our p-wave loss paper has been published!

Our paper entitled “Anomalous loss behavior in a single-component Fermi gas close to a p-wave Feshbach resonance” has been published in Physical Review A on 11/05/2023! In this work put together with the Mixtures team, we developed a theory model and investigate the intriguing loss behaviour in the interacting non-unitary regime. In the thermalising case, we find collisional cooling. In the non-thermalising we find an anomalous density dependence and an evolution toward low energy non-thermalised states. You can learn more here!



03 & 04/2023: Britta and Felix join the group for their bachelor theses!

A few weeks ago, Felix and Britta joined us and started to work on understanding the role of noise in our images and fit results! Felix works on our Lithium imaging and T/TF extraction while Britta focusses on our newly achieved images of Dysprosium BECs. Welcome to both of you and looking forward to exciting discussions!



04/04/2023: We achieve Bose Einstein Condensation of our Dy cloud!

A few days before Easter, we got the best Easter egg in our lab: a BEC of Dy, which we saw inverting its aspect ratio in time of flight. Here is one of its first time-of-flight images, on top of an isotropic thermal background. Since then we have been able to make it pure. Let's see how big we can make it!



09/03/2023: The first paper of the DyLab is on arXiv!

Beginning of March, we submitted the first experimental paper of the Dy lab. This paper reports on the experimental performances of the novel cooling scheme that we implemented in our setup, where we load a narrow-line 3D MOT of dysprosium atoms, directly from a broad-line 2D MOT with a transversely mounted high-temperature oven. The performances are great, you can check for yourself here!



01/03/2023: Valentina submitted her Master thesis

A few days ago, after some unexpected delays and very intense work, Valentina handed in her Master thesis, the second of the QF group! Valentina, I am very proud of you and very impressed that you have managed to put together such a complete and high quality thesis under such difficult conditions and in a fairly short time! I am also very impressed by your careful design and we are very much looking forward to a final version of your accordion and to trapping atoms with it! Thank you for all your work, positive energy and determination. It has been a pleasure to have you in the team!



20/02/2023: Thibault and Charles joins us from France for their Master thesis

Since the end of February, Thibault from the Ecole Normale Supérieur de Paris and Charles from Télécom Strasbourg have joined the Dy lab team for a Master thesis equivalent. They will work on a DMD setup for the tailor trapping of Dy atoms and on the accordion lattice setup from Valentina's Master thesis. Welcome to both of you!



End-of-2022 news: Here a little catch-up on what happened since the start of the Semester

30/12/2022: Our review on dipolar physics with magnetic atoms has been published!

Last minute for 2022, our review article entitled “Dipolar physics: a review of experiments with magnetic quantum gases” has been published in Report on Progress in Physics on 30/12/2022! It has been a collaborative effort over several years to put together this comprehensive work and we hope that many of you will greatly benefit from it. Take a look for yourself here!



01/12/2022: Our additional project A07 of ISOQUANT has been granted and is starting immediately!

Our project entitled “Towards quantum dynamics with dipole-dipole interactions” that we submit at the beginning of 2022 to be integrated within the running collaborative research center ISOQUANT has been granted and started beginning of December. We are very happy to be integrated to the successful collaboration with this new line of research. Follow this link to know more about our project and about ISOQUANT.



05/11/2022: We got our first optically trapped Dy atoms!

In early November, we saw the first atoms being loaded from our 3D magneto-optical trap directly into an optical dipole trap! After optimising this loading, we will proceed with an evaporative cooling process and keep you posted!



10/2022: Maurice joins us for a bachelor internship

Since end of October, Maurice has been joining the Dy Lab team for an internship, before pursuing with his bachelor thesis. He is looking into radio-frequency circuit and antenna to address our ultracold dysprosium atoms!



12/10/2022: Paul is now the third Bachelor of Science of the QF group!

Today, Paul defended his bachelor thesis after well-deserved holidays and this was very successful! Congratulations Paul and thanks for your work and the time among us!



07/10/2022: Jianshun submits his PhD-admission thesis!

Last Friday, Jiasnhun submitted his thesis, the first "PhD admission" thesis of the QF group! Jianshun, I am extraordinarily admirative and proud of the path that we have already travelled together, since the day you join the group — that is to say me at the time, and without neither an office nor a lab… Thank you so much for never lacking will of tackling any challenges and for looking so carefully to things, from theory, to design, and to implementation. We are looking forward for much more fun time together! Furthermore, we thank you for the best ever PhD-admission-thesis acknowledgements in the world! ;)



04/10/2022: Sarah joins the DyLab team!

Beginning of October, Sarah just started her Master project, joining the DyLab team. She will work on characterising and implementing our custom-designed microsocope objective. Welcome Sarah!



May-September 2022: Ohoh, some news delay over the last months… Here a little catch-up!

09/2022: Joschka is the first to finish his Master thesis in the QF group!

A few weeks ago, Joschka handed in his Master thesis, making him the first Master of Science out of the QF group (up to one report)! Joschka, congratulations! We are very proud and immensely grateful that you decided to come down the hill and join our group. We thank you for leaving us with the best coils in the world, and even more for the cool time we spent conceiving them. We thank you for putting all your efforts in finding inventive solutions, for taking on all challenges that the manufacturing process threw at us, and, of course, for all the fun around it too! Now, we wish you a lot of enjoyment on the West Coast and hope to see you for the next BBQ season (at least ;))!



07/2022: Alex from the ERBIUM Innsbruck becomes Doctor!

In July, Alex successfully defended his PhD! We are very proud of him and still sad not to have been able to join the party and discover Meran… It will be for the next time... Before this, we wish him fantastic time and experiences in Canada! Now, only one left from our "Antique" dreamteam!



06/2022: Our paper on Erbium's scattering is published in PRA!

In June, Alex Patscheider got our last paper with the ERBIUM team in Innsbruck accepted in PRA. In this work we investigated different techniques to probe the strength of s-wave scattering among Erbium atoms and performed precision spectroscopy measurements at low magnetic fields. You can learn more by reading here!



05/2022: Britta joined us for a short Hiwi position

Britta joined the Dy Lab team for a "Hiwi" job between may and july 2022. We thank you for your participation and for the good atmosphere! We wish you a good time in Japan and are looking forward to count you among us again in a few months!



08/05/2022: First Dy 3D MOT, loaded from a 2D MOT!

Things go fast. On Saturday the courageous team struck again and succeeded in first trapping Dy atoms in a 3D magneto-optical trap working on the red intercombination line of Dy, being loaded from a blue 2DMOT (red bubble in the center of the picture). Congratulations to the fantastic team! (c) Joschka Schöner.



26/04/2022: Lenny becomes Bachelor of Science!

Today, Lenny is the second student to complete his thesis in the QF-group. He has very respectfully taken up the tradition started by Christian and did a perfect job! He definitely deserved something on his head! Congratulations Lenny, we are very much looking forward to your future work as a HiWi and to the prototype reaching a final design ;) (c) Anonymous friend.



25/04/2022: First Dy 2D MOT!

After some (yet short) peregrinations, we could implement the 2D-MOT optics around the dedicated chamber and courageous team members could see the first 2D-MOT last Saturday (bright line in the picture). (c) Shuwei Jin.



22/04/2022: First atoms fluorescing in our main apparatus!

Two weeks ago, we completed the baking of our main apparatus which is now under ultrahigh vacuum. We switched on our high-temperature oven pre-filled with dysprosium pieces. Sending light transversally to the oven aperture tube in the 2D-MOT chamber, we could observe the first atoms going out of the oven in our main apparatus fluorescing, on the blue as well as on the red transition. Next step: cool the atoms in a 2D-MOT!



19/04/2022: Paul joins the team for his bachelor project.

After a 5-week internship in the group during the semester break, Paul is now starting his bachelor project in the Dy Lab. His project: implementing a setup that enables to general an optical dipole trap for the dysprosium atoms with tuneable anisotropy thanks to a fast time-modulation of the frequency shifts induced by an acousto-optic deflector.



Delayed news! Our review on dipolar physics with magnetic quantum gases is out!

After a long-lasting stop-and-go writing exercise, our review on “Dipolar physics: A review of experiments with magnetic quantum gases” that we put together with Igor Ferrier-Barbut, Francesca Ferlaino, Bruno Laburthe-Tolra, Benjamin L. Lev, and Tilman Pfau is now published on the Arxiv and available at this link! We hope that this review will be useful and become a reference for the community. Despite our great effort to be comprehensive, there might still be some gaps or flaws in our description, and if you notice any mistake or have any comment, please do not hesitate to send me an email! We will be happy to make corrections in a revised version. Enjoy the 99-pages reading!



10/01/2022: We got awarded an ERC Starting grant!

It is now official: we got awarded the 2021 Starting Grant from the European commission for our project 2DDip, “Two-dimensional Dipolar Quantum Gases: Fluctuations and Orders”! That is incredible news for our lab and we are extremely enthusiastic about developing our new project with such support! The next five years promise to be rich! See also our University press release, here.



07/01/2022: The lab is ready and the tables start to be occupied!

After several months, many orders, and lots of work, our lab is finally ready to work and on January 7th, after a bit of delay due to missing pieces, we finally started setting up our cavity! Pumping is going on! For all their efforts during these months, we want to deeply thank the architect and construction offices, the mechanical workshop of the physics institute, the various ordering offices and secretaries, as well as all our colleagues working with us.



08/12/2021: Jean Dalibard is awarded the Médaille d’or du CNRS 2021.

On the 08th of December, Jean Dalibard, Lauriane’s PhD supervisor, received what is considered the highest French award, the Médaille d’Or du CNRS. Again congratulation Jean! Lauriane is really proud and grateful to have taken part in the beautiful ceremony at the Sorbonne University, during which the French Minister of Research gave the award, accompanied by beautiful speeches, inspiring music, an arena of colleagues and friends, and timely magic tricks. By many means, a magic moment.



02/11/2021: Christian defended his thesis.

Today was the first thesis defense of the QF-group history, and Christian did this very well! Congrats again! We are looking forward to welcoming you as a HiWi very soon (as well as to having a small thesis-celebration party, the standard should also be set on this ;) )!



28/10/2021: the group reaches the upper-bound size for pub-quizzing.

On the 21st of October, Lenny joined our team for his bachelor project, and one week later, Joschka organised our first participation to the pub-quizz as Atom Trappers. We finished fifth, not so bad for a first try ;)



15/10/2021: the group takes its distance with zoom.

Mid October, Karthik could finally join us in Heidelberg, and at the Physikalisches Institut in particular, officially starting his PhD. At the same time, we could also finally have our first group meeting in person! Good that we are not always restricted to 2D! (c) Shuwei Jin.



27/09/2021: September news.

A lot happened in September. Prachi finished her internship and is thus the first student to received credits from working in the Quantum-Fluid group. Congrats and good luck for the rest of your studies! Our work with the Er team in Innsbruck on the ultra-narrow line of Er atoms is out on PRR. Nice work that raises interesting prospect for quantum manipulation! Congrats to all coauthors. Valentina travelled from Columbia and just joined our team for her master-thesis project, where she will work on an 2D accordion trap setup for our Dy apparatus. Last but not least, Karthik finally got his visa and will join us soon too!



06/08/2021: August Heidelberg news.

Beginning of August, our motivated but pictureless postdoc joined the Dy team! Welcome Shuwei! Taking advantage of the reopening of Ziegelhausen III, Lauriane could finally enjoy the famous Supercrack. Credit for the picture of this latter event: Markus Neumann.



22/07/2021: Our Bragg spectroscopy study of dipolar Supersolidity performed with the Er team in Innsbruck (Ferlaino group) is finally published in PRA!

In this work, we studied the response of dipolar quantum gases to large-momentum Bragg excitations in the quasi-free particle regime, along the superfluid/supersolid/normal solid phase diagram. At the transition from superfluid to supersolid, the response amplitude decreases highlighting the apparition of density patterns. Yet the observed response reduction exceeds that from theoretically expected steady state. By comparing observations to theoretical predictions, our work highlights the central role played by coherent phase dynamics at the crossing of the phase transition in experiments. Check it out here.



13/07/2021: Joschka starts his master project, Prachi joins for a short internship.

On the 12th of July, Joschka started his master thesis project in which he will build the 3D MOT for our Dy lab. A few weeks earlier, Prachi also started a short internship in our Dy team looking at flat-top beams for our 2D-MOT. Welcome!



15/06/2021: Tobias and Michael join the mixture team!

On the 15th of June, Tobias and Michael had their first day as PhD student on the Mixture experiment. Michael is not exactly new to the group and joins us in full knowledge ;) Tobias joins us from Karlsruhe where he did his master thesis on optical fiber-based micro resonators. Welcome to both of them!



07/06/2021: Our latest work with the Dy team in Innsbruck (Ferlaino group) is now in PRL and featured in APS Physics Viewpoint and Physics World!

Our work in which we experimentally study the evaporation process into supersolid states in harmonically trapped cigar-shaped Dy Bose gases is now published. Check it out here, and also have a look at this nice coverage, here and there. In this work, we in particular observe that, in the evaporation process, density modulation first appears locally and precedes global phase coherence. (c) Carin Cain



11/05/2021: The Dy team gets bigger!

Beginning of May, Christian joined the group as a first bachelor student on the Dy team. He will help designing the experiment's vacuum apparatus. Karthik, who should have arrived in Heidelberg and joined us a PhD student, is unfortunately unable to travel from India due to the current sanitary situation. He is however joining us from distance! Welcome to both of you!



11/03/2021: Lauriane becomes member of the SFB ISOQUANT!

On March 11th, Lauriane was unanimously elected to be new principal investigator within the Collaborative Research Centre 1225 ISOQUANT! She now joins as a member of Project C)3, and will be keen on developing new projects soon within this extraordinary community of collaborators! For more info on the collaboration, see here.



01/03/2021: Jianshun joins the team!

On March 1st, Jianshun Gao joins the quantum-fluid group as first student in the new Dy Lab. Jianshun just arrived from China where he graduated from Nankai University. Jianshun was awarded a grant from the IMPRS Doctoral School in "4+4" program type. Welcome Jianshun and good start!


01/02/2021 - Lauriane arrived at Heidelberg University

On February 1st, Lauriane received her nomination as Junior Professor of Heidelberg University. She is now starting setting up her group and her new lab in the first floor of the Physikalisches Institut. She will start teaching on the summer semester 2021. A proper celebration will be held once COVID allows ;)