LKB - Polarised Helium, Quantum Fluids and Solids


News and Events

Regular article

Optical measurement of the equation of state of bulk liquid helium-4 around 1 K, L. Djadaojee, J. Grücker, Phys. Rev. B 103, 144513 (2021) [5 pages]


Using a stimulated Brillouin gain spectroscopy technique, we have measured the equation of state of bulk liquid helium-4 at 1 K between 0 and 10 bars. Our results are in very good agreement with previous measurements and with theoretical equations of state. However, our specific method allows one to determine it on space/timescales as narrow as 35 μm/190 ns. This technique is of particular interest for solving a remaining debate about the value of the homogeneous cavitation pressure of liquid 4He at T1 K.

Regular article


The HELPING project (2021-2025)

High field Enhancement of nucLear Polarisation In Noble Gases.
LKB (Coord. G. Tastevin) – NIMBE (Sc. Lead. G. Huber).

Summary / RésuméOpen positions:
1 PhD (LKB) : Job offer
1 Post-Doc (NIMBE) : Job offer

Regular article

Nuclear hyperpolarization of ³He by magnetized plasmas, Maul A., Blümler P., Nacher P.-J., Otten E., Tastevin G., and Heil W., Phys. Rev. A (2018) 98, 063405 [12 pages]

Review article

Optically polarized ³He, T. R. Gentile, P. J. Nacher, B. Saam, and T. G. Walker, Rev. Mod. Phys. 89, 045004 (2017)

Regular article

Doppler-free spectroscopy of the lowest triplet states of helium using double optical resonance, A. Dia, M. Abboud, P.-J. Nacher, and G. Tastevin – Eur. Phys. J. D (2021) 75:223 – SharedIt link


Optical pumping on the 2³S-2³P transition (1083 nm) of metastable ³He or 4He atoms is used for scienceand applications. We report on its combination with an optical probe on the 2³P-3³S transition (706.5 nm) ina ladder-type double optical resonance scheme, with cw single-frequency pump and probe diode lasers. Theoreticalexpectations for level structure and absorption spectra were computed for both isotopes. Narrow Doppler-free spectrallines were experimentally obtained in low-pressure gas samples. The line weights and their Zeeman structure in weakmagnetic eld agreed with expectations. The precision of the line positions and line splittings was limited by genericerrors of our commercial Fizeau wavemeter, which were independently characterised. The potential of this doubleresonance scheme for spectroscopic measurements on the three lowest triplet states of He was evaluated. The relevanceof velocity- and sublevel-selective pumping combined with polarisation spectroscopy of probe absorption for a studyof pressure-dependent population transfers in the 2³P state was established.

PhD defense

Ali DIA gradutated from ENS-PSL (Paris) and USJ (Beyrouth) on May 7, 2021.
Experimental study of redistribution and exchange collisions in the 2³P level of helium

The MARGIN project (2020-2022)

MAgnetic Resonance studies of Gas diffusion In Nanoporous materials.
LKB (Coord. P.-J. Nacher) – MRS Lab, Kazan Fed. Univ. (Coord. M. Tagirov))

Project homepage  – Project overview
The Post-Doc position is now closed.

PhD student

Lionel DJADAOJEE (Teaching assistant at ENS Paris – PSL, Agrégé de Physique) has joined the group for PhD work on the metastable phases of solid and liquid 4He (J. Grücker, superviser; Sept. 2019 – …).


March 2019, PSL-iTeams closing session.

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MULSA (an ecologically responsible alternative to conventional foam board) has been selected as best project at the end of the 2018/2019 PSL-iTeams training program (entrepreneurship education for PSL Master and PhD students, promoting interdiscplinarity and innovation). The project has been designed and defended on March 26 by Fiona Guillemant (ENSAD 2018), Baptiste Lefebvre ( PhD student, ENS), and Ali Dia.

In memoriam

Philippe Jacquier, leader of the “Quantum solid and liquid helium” team since 2003, passed away on Jan.24, 2019.

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Philippe has battled against disease for many years with impressive courage and steadfast determination. He was an excellent teacher and a passionate researcher. The group will long miss his deep sense of humour and friendship, as well as the enthousiasm, the inventiveness, the curiosity, and the broad knowledge that made working with him so pleasant every day.

Short text (in French) by Antoine Heidmann, Director of the LKB.Ph. Jacquier’s scientific homepage


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Polarised He & quantum fluids
Quantum solid & liquid He
  • Franck Laloë
  • Pierre-Jean Nacher
  • Geneviève Tastevin
  • Polar. 3He - Other People
  • Ali Dia
  • Jules Grucker
  • Solid 4He - Other people
  • Lionel Djadaojee

Recent Papers

A. Maul, P. Blümler, P.-J. Nacher, E. Otten, G. Tastevin, and W. Heil

Phys. Rev. A 98, 063405 (2018)

T. R. Gentile, P. J. Nacher, B. Saam, and T. G. Walker

Rev. Mod. Phys. 89, 045004 (2017)

L. Djadaojee, A. Douillet, and J. Grücker

Eur. Phys. J. Appl. Phys. 89, 30701 (2020)

Jules Grucker

J. Low. Temp. Phys. 197, 149–166 (2019)

G. Tastevin and F. Laloë

Eur. Phys. J. D 72: 183 (2018)

M.E. Hayden, and P.-J. Nacher

Magn. Reson. Imaging Handbook, 1, CRC press, 2016 (Ed. Luca SABA)

P.-J. Nacher, S. Kumaragamage, G. Tastevin, and C.P. Bidinosti

J. Magn. Reson. 310, 106638 (2020)

V. Kuzmin and P.-J. Nacher

J. Magn. Reson. 310, 106622 (2020)


2021 - Master / PhD (ANR funding)

Hyperpolarisation of ³He nuclear spin at moderate/high magnetic field

M2 internship work: Unveiling the mechanism for nuclear spin self-orientation in ³He gas discharges.
Type of work: Instrumental, experimental.
Context and objectives: Read a 1-page summary - Visit our website - Contact us.

Opening for PhD: Come and join the team for a 3-year contribution to the HELPING project focused on the control of ³He nuclear spin state in magnetised rf gas discharges!
This project provides a unique opportunity for basic and applied research work, as well as for training in a variety of techniques such as laser spectroscopy, optical polarimetry, NMR measurements and imaging, cryogenics, to name a few.

More about recruitment

Full financial support is available (ANR funding). Recruitment should be completed by September 2021. Talented and highly motivated students are most welcome to send usual documents (letter of application, CV, and references re. prior experience with lab or experimental work). Please note that women are warmly encouraged to apply for this positionThe ANR supports women wishing to engage in scientific careers and encourages the young generations to join all fields of research. We are committed to gender equality and consideration of sex and/or gender aspects as included, e.g., in the French or European Code of Ethics and Scientific Integrity..

2021 - Master 2 / PhD



Low field MRI - Polarised helium-3

Skilled and motivated students are welcome to join our investigations on low field MRI with laser-polarised ³He gas or thermally-polarised water samples. Work may focus on the impact of concomitant field gradients on image quality, or investigate the short-pulse limit and revisit the Bloch-Siegert effect in pulsed NMR. This topic is open for PhD.

2021 - L3 internship

Measurements of magnetic field strengths in a low-field MRI system

Mesures de champs magnétiques dans un système pour l’IRM à bas champ

Objective: Use and comparison of different methods allowing measurement of the magnetic field strengh.

Context: Magnetic resonance imaging typically involves a static (main) field, pulsed (imaging) field gradients, and oscillatory (rf) fields. For low field operation, various types of devices or magnetic sensors may be used for accurate control of, both, applied and stray fields.

Work: Physical measurements, data acquistion (output voltages). MRI tests, data analysis, correlation with image features.

2021 - Post-Doc position

MAgnetic Resonance studies of Gas diffusion In Nanoporous materials (MARGIN)

Context: Collaborative research project involving the Laboratoire Kastler Brossel (ENS-PSL, Paris) and the MRS Lab (Kazan Fed. Univ., Kazan, Russian Federation).

Objective: Investigations of gas diffusion in nano-scale void spaces at low and high temperature. Assessment of the influence of the attractive wall potential on molecular gas dynamics, so far overlooked in standard diffusion models.

Work : Use ³He as a probe gas and measure the apparent diffusion coefficient at room temperature in different porous systems, such as ordered aerogels, nanopowders, etc. Perform NMR and MRI experiments at low field (mT), using hyperpolarisation by laser optical pumping for high detection sensitivity. Make numerical simulations of restricted gas diffusion for reliable interpretation of the experimental findings.

Funding of the project: Joint ANR-RSF grant.

Location: LKB, Department of Physics of ENS, 24 rue Lhomond, 75005 Paris, France

Duration: 18 to 24 months, depending on the applicant's qualifications

Master 2 internship


Polarised helium - Liquid NMR

Skilled and motivated students are welcome to join the team for follow-up of our investigations on liquid NMR in laser polarised ³He-⁴He dilute solutions. Work will deal with the latest observations of non linear NMR dynamics and will focus on the comparison between experimental and numerical data. This topic is not open for PhD this year.

We are always looking for brillant motivated scientists to join our group.

Check the open positions (see above) or send us your CV for application.


Département de Physique Ecole Normale Supérieure, 24 rue Lhomond, F-75231 Paris Cedex 05  

  •  Jules Grucker  : jules.grucker at
  • Franck Laloë : laloe at
  • Pierre-Jean Nacher : nacher at
  • Geneviève Tastevin : genevieve.tastevin at

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