NOVEL QUANTUM PHASES OF MATTER: FROM A POSSIBLE HEXATIC FLUID IN 2D 4HE TO THE STUDY OF COLD FERMIONIC GASES WITH HIS(N) SYMMETRY

Operation co-funded by EU cohesion policy (European Regional Development Fund (ERDF)) under the programme Multi-regional Spain - ERDF (2014ES16RFOP002), managing authority: Subdirección General de Gestión del FEDER, de la Dirección General de Fondos Europeos del Ministerio de Hacienda.. The source names no beneficiary for this operation. Location: Seville Province (NUTS ES618); Spain. Budget: total eligible expenditure EUR 10,043; EU co-financing EUR 8,034.4 (co-financing rate 80%), as stated by the source. Runs 2018-01-01 to 2021-09-30. Source: Kohesio, EU cohesion policy projects managed by national and regional authorities (not CORDIS). Summary from Kohesio (English machine translation by the source): THE SECOND SUBPROJECT WITHIN THE PROPOSAL WILL HAVE TWO GOALS. IN THE FIRST ONE, WE WILL TRY TO DISTINGUISH BETWEEN THE CONTRADICTORY PICTURES GIVEN BY TWO VERY RECENT EXPERIMENTAL WORKS ON THE DESCRIPTION OF THE SECOND LAYER OF 4HE ON GRAPHITE. WHEN USING CALORIMETRIC MEASUREMENTS, EITHER A QUANTUM HEXATIC PHASE OR A NEW COMMENSURATE ONE IS FOUND WITHIN THE STABILITY RANGE OF THE INCOMMENSURATE SOLID DESCRIBED IN PREVIOUS THEORETICAL CALCULATIONS. ON THE OTHER HAND, TORSIONAL OSCILLATOR EXPERIMENTS SUGGEST THE EXISTENCE OF A TWO-DIMENSIONAL SUPERSOLID IN THE SAME HELIUM DENSITY RANGE. THIS WOULD BE THE FIRST EXPERIMENTAL REALIZATION OF A SUPERFLUID SOLID. BOTH PICTURES ARE ALSO AT ODDS WITH THE EXTANT THEORETICAL DESCRIPTIONS OF THE SYSTEM. WHAT WE PROPOSE IS TO PERFORM DIFFUSION MONTE CARLO (DMC) CALCULATIONS TO SOLVE THE SCHRODINGER EQUATION THAT DESCRIBES A TWO-LAYER ARRAGEMENT OF 4HE ATOMS ON GRAPHITE, USING AS INITIAL APPROXIMATIONS (THE TRIAL FUNCTIONS OF THE METHOD) IMPROVED WAVEFUNCTIONS FOR AN HEXATIC PHASE OR A (COMMENSURATE OR INCOMMENSURATE) SUPERSOLID. THE ONE WITH THE MINIMUM ENERGY IS EXPECTED TO DESCRIBE BETTER THE GROUND STATE OF THE SECOND LAYER OF 4HE ON GRAPHITE. THIS WOULD BE A DIRECT CONTINUATION OF CALCULATIONS MADE BY MEMBERS OF THE FIRST AND SECOND SUBGROUPS WORKING TOGETHER. ON THE OTHER HAND, WE PROPOSE TO STUDY THE BEHAVIOUR OF ULTRACOLD FERMIONIC ISOTOPES OF YTTERBIUM (173YB AND 171YB) LOADED IN ONE-DIMENSIONAL OPTICAL LATTICES. THAT WOULD MEAN TO CONSIDER ARRANGEMENTS WITH SU(6) (173YB) AND SU(6)X SU(2) SYMMETRIES, IN A DIRECT CONTINUATION OF THE WORK ALREADY DONE AND IN PROGRESS FOR SU(2) SYSTEMS. THOSE MIXTURES (AND THE PURE SETUP WITH ONLY 173YB) HAVE BEEN EXPERIMENTALLY LOADED IN THREE-DIMENSIONAL OPTICAL LATTICES, AND IN ONE-DIMENSIONAL HARMONICALLY CONFINED TUBES (173YB). THE GOAL WILL BE TO ASCERTAIN IF THE SU(6) SYMMETRY OF THE 173YB FERMIONS PRODUCE NEW AND EXOTIC PAIRINGS, LIKE THE FORMATION OF "HEXIONS" (ALONE OR WHEN [shortened; the full text is on the Kohesio page]

Original source.

Source: Kohesio (EU cohesion policy projects), European Commission, Directorate-General for Regional and Urban Policy (DG REGIO). Retrieved 2026-10-21. Licence: CC0 1.0 (Cohesion Open Data Platform, dataset 2014-2020 Kohesio projects). Selected metadata, adapted presentation; the publisher's record is authoritative. No endorsement by the source is implied. Licence: public domain dedication (CC0 1.0).

AI-assisted summary: The operation, co-funded by the EU under the Multi-regional Spain programme, focuses on distinguishing between two experimental descriptions of the second layer of 4He on graphite. It runs from January 1, 2018, to September 30, 2021, with a budget of EUR 10,043. Suggested technology pillar: simulation. Generated by AI from the public source text; it may contain errors and the original source is authoritative.