Fermionic versus bosonic behavior of confined Wigner molecules

Cuestas, Eduardo; Bouvrie, P. Alexander; Majtey, Ana P.

doi:10.1103/physreva.101.033620

Cited by 12 publications

(11 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When the available space defined by the trap is large compared to the size of the pairs, the trap enhances the closed channel fraction in line with the intuitive notion that the trap forces the pairs to be in a molecular state. This is possible because the availability of enough space in the real space is related to the availability of sufficient space in the state space [21,22]. When the size of the molecules begins to be comparable to the trap's characteristic length, the trap acts as a buffer for the closed channel contribution.…”

Section: For the Last Definitions We Used Q2mentioning

confidence: 99%

A generalized molecule approach capturing the Feshbach-induced pairing physics in the BEC–BCS crossover

Cuestas¹,

Majtey²

2021

J. Phys.: Condens. Matter

Self Cite

View full text Add to dashboard Cite

By including the effect of a trap with characteristic energy given by the Fermi temperature T F in a two-body two-channel model for Feshbach resonances, we reproduce the measured binding energy of ultracold molecules in a 40K atomic Fermi gas. We also reproduce the experimental closed-channel fraction Z across the BEC–BCS crossover and into the BCS regime of a 6Li atomic Fermi gas. We obtain the expected behavior Z ∝ T F at unitarity, together with the recently measured proportionality constant. Our results are also in agreement with recent measurements of the Z dependency on T F on the BCS side, where a significant quantitative discrepancy between experimental data and theory’s predictions has been repeatedly reported. In order to contrast with future experiments we report the proportionality constant at unitarity between Z and T F predicted by our model for a 40K atomic Fermi gas.

show abstract

Section: For the Last Definitions We Used Q2mentioning

confidence: 99%

A generalized molecule approach capturing the Feshbach-induced pairing physics in the BEC–BCS crossover

Cuestas¹,

Majtey²

2021

J. Phys.: Condens. Matter

Self Cite

View full text Add to dashboard Cite

show abstract

“…This features are in complete agreement with the results obtained in Refs. [42,43], in which the availability of enough space in the real space was related to the availability of sufficient space in the state space.…”

Section: The Ground State: Representations and Entanglementmentioning

confidence: 99%

Entanglement and fermionization of two distinguishable fermions in a strict and non strict one-dimensional space

Cuestas¹,

Jiménez²,

Majtey³

2020

J. Phys. A: Math. Theor.

Self Cite

View full text Add to dashboard Cite

The fermionization regime and entanglement correlations of two distinguishable harmonically confined fermions interacting via a zero-range potential is addressed. We present two alternative representations of the ground state that we associate with two different types of one-dimensional spaces. These spaces, in turn, induce different correlations between particles and thus require a suitable definition of entanglement. We find that the entanglement of the ground state is strongly conditioned by those one-dimensional space features. We also find that in the strongly attractive regime the relative ground state is a highly localized state leading to maximum entanglement. Our analysis shows that in the strongly repulsive regime the ground state changes smoothly from a superposition of Slater-like states to a finite superposition of Slaters, this lack of accessible states yields to Pauli blocking as a strong signature of fermionization. Our results indicate that entangled states could be obtained in current experiments by reaching the non-interacting regime from the interacting regime. Entangled states could also be obtained when a state is brought from the interacting regime into the strongly repulsive regime by changing the scattering length near the confinement-induced resonance. Finally, we show that the first excited state obtained in the absence of interactions and the third excited fermionized state are maximally entangled.

show abstract

“…Its finite counterparts, e.g. Wigner molecules [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] are formed in quantum dots at low electron numbers in spatially large systems [5] or in a strong magnetic field that promotes the single-electron localization [22,23].…”

Section: Introductionmentioning

confidence: 99%

“…For this reason in circular quantum dots, separation of the electrons in the Wigner phase occurs only in the inner coordinates of the system spanned by relative electron-electron distances [22]. For lowered symmetry, the Wigner molecules can appear in the laboratory frame [24], with the special case of one-dimensional systems that is studied with much of attention [6,9,16,20,21].…”

Section: Introductionmentioning

confidence: 99%

Wigner molecules in phosphorene quantum dots

Thakur¹,

Szafran²

2022

Preprint

View full text Add to dashboard Cite

We study Wigner crystallization of electron systems in phosphorene quantum dots with confinement of an electrostatic origin with both circular and elongated geometry. The large effective masses in phosphorene promote the separation of the electron charges already for quantum dots of relatively small size. The anisotropy of the effective mass allows for the formation of Wigner molecules in the laboratory frame with a confined charge density that has lower symmetry than the confinement potential. We find that in circular quantum dots separate single-electron islands are formed for two and four confined electrons but not for three trapped carriers. The spectral signatures of the Wigner crystallization to be resolved by transport spectroscopy are discussed. Systems with Wigner molecule states are characterized by a nearly degenerate ground state at B = 0 and are easily spin-polarized by the external magnetic field. In electron systems for which the single-electron islands are not formed, a more even distribution of excited states at B = 0 is observed, and the confined system undergoes ground state symmetry transitions at magnetic fields of the order of 1 Tesla. The system of five electrons in a circular quantum dot is indicated as a special case with two charge configurations that appear in the ground-state as the magnetic field is changed: one with the single electron islands formed in the laboratory frame and the other where only the pair-correlation function in the inner coordinates of the system has a molecular form as for three electrons. The formation of Wigner molecules of quasi-1D form is easier for orientation of elongated quantum dots along the zigzag direction with heavier electron mass. The smaller electron effective mass along the armchair direction allows for freezing out the transverse degree of freedom in the electron motion. Calculations are performed with a version of the configuration interaction approach that uses a single-electron basis that is pre-optimized to account for the relatively large area occupied by strongly interacting electrons allowing for convergence speed-up.

show abstract

Fermionic versus bosonic behavior of confined Wigner molecules

Cited by 12 publications

References 46 publications

A generalized molecule approach capturing the Feshbach-induced pairing physics in the BEC–BCS crossover

A generalized molecule approach capturing the Feshbach-induced pairing physics in the BEC–BCS crossover

Entanglement and fermionization of two distinguishable fermions in a strict and non strict one-dimensional space

Wigner molecules in phosphorene quantum dots

Contact Info

Product

Resources

About