Testing the validity of Bose-Einstein statistics in molecules

Studying fundamental physics using quantum enabled technologies with trapped molecular ions

“…12 Precise spectroscopic measurements with molecules have indeed increasingly been used in the last decade to test fundamental symmetries (parity (66 , 67 ), or parity and time-reversal, a signature of which would be the existence of a non-zero electron EDM, see note 1 ) and postulates of quantum mechanics (68 ), to measure either absolute values of fundamental constants (such as the Boltzmann constant k B (69 , 70 ), or the protonto-electron mass ratio µ, with recently the first determination of µ from a molecular system (71 )), or their variation in time (fine structure constant α (72 ), proton-to-electron mass ratio µ, see note 2 ) 13 Over the last few years, several techniques for the production of molecular ions have emerged and are reviewed in (65 ). The technique pioneered by the Drewsen group consists in first trapping an atomic ion of interest, usually produced by ionization of a neutral atomic gas, and then leaking in neutral molecular gas to react with the atomic ions and produce the desired molecular ions (22 ).…”

Tunable Microcavity-Stabilized Quantum Cascade Laser for Mid-IR High-Resolution Spectroscopy and Sensing

“…Narrow-linewidth frequency-stabilized lasers having mid-IR emission wavelengths have been demonstrated as the most suitable sources for both high-resolution and high-sensitivity molecular spectroscopy. The strong molecular rovibrational transitions that can be accessed with mid-IR laser sources have allowed trace-gas sensing down to the parts-per-quadrillion level [ 1 ] and frequency metrology on simple molecules, showing the potential for testing fundamental principles of physics at <1 eV energy scales [ 2 , 3 , 4 , 5 , 6 ]. Room temperature quantum cascade lasers (QCLs) are particularly attractive for these applications because they emit in the mid IR, with an mW to W optical power level and a wide spectral coverage.…”

Revealing Quantum Statistics with a Pair of Distant Atoms

“…While more general quantum statistics [2] are in principle conceivable, they seem not to be realized by elementary particles in nature [3].The influence of the wavefunction symmetry has been spectacularly demonstrated in few-particle systems with Hong-Ou-Mandel-like interference experiments [4][5][6][7][8], and in many-body systems with ultracold quantum gases [9]. Spectroscopic experiments have also tested the symmetrization postulate for massive particles [10][11][12][13][14] and for photons [15,16] with high precision. Recently, exchange interactions have been applied in engineered quantum systems for entangling pairs of atoms or electrons [17][18][19][20].At the most elementary level, the wavefunction symmetry manifests itself when two identical particles are exchanged in position [ Fig.…”

“…Exchange of identical particles can naturally occur in molecules where identical, distant nuclei may be interchanged as a result of a rotation [21]. Prior experiments [10][11][12][13][14] have exploited this naturally occurring exchange of identical particles to show that only certain rotational states are permitted by the symmetrization postulate. However, a direct interferometric measurement of the exchange phase ϕ ex has never been attempted.…”