Majorana modes and<i>s</i>-wave topological superfluids in ultracold fermionic atoms

Wu, Ya-Jie; Li, Ning; Zhou, Jiang; Kou, Su-Peng; Yu, Jing

doi:10.1088/0953-4075/49/18/185301

Cited by 3 publications

(4 citation statements)

References 37 publications

(43 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With our equations we find the same functional behavior for T BKT as a function of U but our results are exactly a factor of two larger than those presented in [66]. The reason for this difference is because in [66], the phase fluctuations of the order parameter are rescaled by a factor of 1/ √ 2 [see equation (33) in [66]]. With this rescaling, the periodicity of the φ field in (38) becomes 2 √ 2π and therefore the expression for the BKT transition temperature [equation (39)] should be multiplied by a factor of 2.…”

Section: Appendix B: Geometric Contribution Of the Superfluid Weightsupporting

confidence: 72%

“…Furthermore, we have checked that in the continuum limit our expression for the superfluid weight reduces to the expressions presented in [58] where BCS states in spinorbit-coupled 2D continuum were considered. We also benchmarked our equations by computing T BKT in case of BCS phases for a 2D square lattice geometry with the same parameters that were used in [66] where topological BCS states in the presence of the SOC were studied. With our equations we find the same functional behavior for T BKT as a function of U but our results are exactly a factor of two larger than those presented in [66].…”

Section: Discussionmentioning

confidence: 99%

“…We also benchmarked our equations by computing T BKT in case of BCS phases for a 2D square lattice geometry with the same parameters that were used in [66] where topological BCS states in the presence of the SOC were studied. With our equations we find the same functional behavior for T BKT as a function of U but our results are exactly a factor of two larger than those presented in [66]. The reason for this difference is because in [66], the phase fluctuations of the order parameter are rescaled by a factor of 1 2 (see equation (33) in [66]).…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Superfluid weight and Berezinskii–Kosterlitz–Thouless temperature of spin-imbalanced and spin–orbit-coupled Fulde–Ferrell phases in lattice systems

2018

View full text Add to dashboard Cite

We study the superfluid weight D s and Berezinskii-Kosterlitz-Thouless (BKT) transition temperatures T BKT in case of exotic Fulde-Ferrell (FF) superfluid states in lattice systems. We consider spinimbalanced systems with and without spin-orbit coupling (SOC) accompanied with in-plane Zeeman field. By applying mean-field theory, we derive general equations for D s and T BKT in the presence of SOC and the Zeeman fields for 2D Fermi-Hubbard lattice models, and apply our results to a 2D square lattice. We show that conventional spin-imbalanced FF states without SOC can be observed at finite temperatures and that FF phases are further stabilized against thermal fluctuations by introducing SOC. We also propose how topologically non-trivial SOC-induced FF phases could be identified experimentally by studying the total density profiles. Furthermore, the relative behavior of transverse and longitudinal superfluid weight components and the role of the geometric superfluid contribution are discussed.performed with quasi-one-dimensional population-imbalanced atomic gases have shown to be consistent with the existence of the FFLO state [33] but unambiguous proof is still missing.In addition to conventional spin-imbalanced quantum gas experiments, recently also synthetic SOC and Zeeman fields have been realized in ultracold gas experiments [34][35][36][37][38] which makes it possible to investigate SOC-induced FFLO states as well. As SOC-induced FFLO states have been predicted to be stable in larger parameter regime than conventional spin-imbalanced FFLO phases [10], synthetic SOC could provide a way to realize FFLO experimentally in ultracold gas systems [15].Low dimensionality has been predicted to favor 40]. However, in two and lower dimensional systems thermal phase fluctuations of the Cooper pair wave functions prevent the formation of true superfluid long range order as stated by the Mermin-Wagner theorem [41]. Instead, only quasi-long range order is possible. In two-dimensions, the phase transition from a normal Fermi gas to a superfluid state of quasi-long range order is determined by the Berezinskii-Kosterlitz-Thouless (BKT) transition temperature T BKT [42]. Below T BKT the system is a superfluid and above T BKT superfluidity is lost.In recent years, SOC-induced FFLO phases in two-dimensional systems have gained considerable attention [7,10,13,14,20,21,25]. In these systems it has been argued that SOC accompanied with the in-plane Zeeman field would yield FFLO states. Furthermore, in [13,14] it was predicted that in the presence of the out-of-plane Zeeman field, i.e. spin-imbalance, SOC-induced FFLO states could be topologically non-trivial and support Majorana fermions. Such topological FFLO states are conceptually new and exotic superconductive phases of matter. However, these studies were performed by applying mean-field theories which do not consider the stability of FFLO states against thermal phase fluctuations in terms of the BKT transition. Superfluidity and BKT transition temperatures of BCS phases in spin-...

show abstract

Section: Appendix B: Geometric Contribution Of the Superfluid Weightsupporting

confidence: 72%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Superfluid weight and Berezinskii–Kosterlitz–Thouless temperature of spin-imbalanced and spin–orbit-coupled Fulde–Ferrell phases in lattice systems

2018

View full text Add to dashboard Cite

show abstract

“…In recent years remarkably experimental progress has been made including the realization of Hubbard model [35], BCS pairing [36] and various topological quantum matter [37], as well as transport measurements with cold atoms [38]. In particular, at this platform, p x + ip y SFs or non-Abelian s-wave SFs are proposed in spin-orbit coupled cold atoms [39], where Majorana zero modes localize at SF vortex cores or ends of the edge dislocations [40,41]. Generally, by tuning the s -wave scattering length through Feshbach resonance technique, the s-wave attractive interaction between atoms can be fine tuned, so that s-wave Cooper pairing can be reached readily.…”

Section: Introductionmentioning

confidence: 99%

Majorana corner modes in an s-wave second order topological superfluid

Gao

et al. 2020

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We propose a method to prepare Majorana pairs at the corners of imprinted defects on a twodimensional cold atom optical lattice with s-wave superfluid pairing. Different from previous proposals that manipulate the effective Dirac masses, our scheme relies on the sign flip of the spin-orbit coupling at the corners, which can be tuned in experiments by adjusting the angle of incident Raman lasers. The Majorana corner pairs are found to be located at the interface between two regimes with opposite spin orbit coupling strengths in an anticlockwise direction and are robust against certain symmetry-persevered perturbations. Our work provides a new way for implementing and manipulating Majorana pairs with existing cold-atom techniques. arXiv:2006.06905v1 [cond-mat.quant-gas]

show abstract

Majorana modes and topological superfluids for ultracold fermionic atoms in anisotropic square optical lattices

Kou

2016

Eur. Phys. J. B

View full text Add to dashboard Cite

Majorana modes ands-wave topological superfluids in ultracold fermionic atoms

Cited by 3 publications

References 37 publications

Superfluid weight and Berezinskii–Kosterlitz–Thouless temperature of spin-imbalanced and spin–orbit-coupled Fulde–Ferrell phases in lattice systems

Superfluid weight and Berezinskii–Kosterlitz–Thouless temperature of spin-imbalanced and spin–orbit-coupled Fulde–Ferrell phases in lattice systems

Majorana corner modes in an s-wave second order topological superfluid

Majorana modes and topological superfluids for ultracold fermionic atoms in anisotropic square optical lattices

Contact Info

Product

Resources

About