arXiv:2303.09186

Competition of superfluid phases in low-dimensional spin-$1\over 2$ fermions with $s$- and $p$-wave interactions

Alona Nikolaeva, Orest Hryhorchak, V. Pastukhov

Published Mar 16, 2023• 0 citations

Abstract

The ground state of spin-$1\over 2$ fermions with contact $s$-wave inter- and $p$-wave intra-species interactions is discussed. Particularly, we formulate the mean field scheme for calculating thermodynamic properties of the system in arbitrary dimension $D<2$ and discuss in detail the phase diagram in 1D case. Except clean phases with either singlet or triplet Cooper pairings, we have identified two mixed phases (one stable and another metastable) of the one-dimensional two-component fermions where both pairing mechanisms coexist.

DOI: 10.48550/arxiv.2303.09186

Related papers

Competition of superfluid phases in low-dimensional spin-½ fermions with s- and p-wave interactions

Alona Nikolaeva, Orest Hryhorchak, V. Pastukhov

Jun 17, 20250 citations

Competition between pairing and tripling in one-dimensional fermions with coexistent s - and p -wave interactions

Yixin Guo, Hiroyuki Tajima

arXiv:2210.07042Physical review. B./Physical review. BJan 31, 20237 citations

Asymmetric fermion superfluid with inter- and intra-species pairings

Xu-Guang Huang, Xuewen Hao, Pengfei Zhuang

We investigate the phase structure of an asymmetric fermion superfluid with inter- and intra-species pairings. The introduction of the intra-species pairing mechanism in canonical ensemble changes significantly the phase diagram and brings in a new state with coexisting inter- and intra-species pairings. Different from the case with only inter-species pairing, all the fermion excitations are fully gapped in the region with intra-species pairing.

arXiv:cond-mat/0610610New Journal of PhysicsOct 19, 20077 citations

Mean-field phase diagram of the Bose-Fermi Hubbard model

Marin Bukov, Lode Pollet

arXiv:1311.7148Physical Review BMar 4, 201428 citations

PAIRING IN ASYMMETRICAL FERMI SYSTEMS

Khandker Quader, Renyuan Liao

International Journal of Modern Physics BMay 30, 20070 citations

Pairing in asymmetrical Fermi systems with intra- and interspecies correlations

Renyuan Liao, Khandker Quader

arXiv:cond-mat/0611421Physical Review BDec 7, 20075 citations

arXiv:2303.09186

Competition of superfluid phases in low-dimensional spin- $1\over 2$ fermions with $s$ - and $p$ -wave interactionsCompetition of superfluid phases in low-dimensional spin-$1\over 2$ fermions with $s$- and $p$-wave interactions

Alona Nikolaeva, Orest Hryhorchak, V. Pastukhov

Published Mar 16, 2023• 0 citations

arXiv HTML PDF

Abstract

The ground state of spin-

1\over 2

fermions with contact

s

-wave inter- and

p

-wave intra-species interactions is discussed. Particularly, we formulate the mean field scheme for calculating thermodynamic properties of the system in arbitrary dimension

D<2

and discuss in detail the phase diagram in 1D case. Except clean phases with either singlet or triplet Cooper pairings, we have identified two mixed phases (one stable and another metastable) of the one-dimensional two-component fermions where both pairing mechanisms coexist.

DOI: 10.48550/arxiv.2303.09186

Related papers

Competition of superfluid phases in low-dimensional spin-½ fermions with s- and p-wave interactions

Alona Nikolaeva, Orest Hryhorchak, V. Pastukhov

Abstract The ground state of spin- $1/2$ fermions with contact $s$ -wave inter- and $p$ -wave intra-species interactions is discussed. Particularly, we formulate the mean field scheme for calculating thermodynamic properties of the system in arbitrary dimension $D<2$ and discuss in detail the phase diagram in the 1D case. Except for clean phases with either singlet or triplet Cooper pairings, we have identified two mixed phases (one stable and another metastable) of the one-dimensional two-component fermions where both pairing mechanisms coexist. PACS numbers: 67.85.-dAbstract The ground state of spin-$1/2$ fermions with contact $s$-wave inter- and $p$-wave intra-species interactions is discussed. Particularly, we formulate the mean field scheme for calculating thermodynamic properties of the system in arbitrary dimension $D<2$ and discuss in detail the phase diagram in the 1D case. Except for clean phases with either singlet or triplet Cooper pairings, we have identified two mixed phases (one stable and another metastable) of the one-dimensional two-component fermions where both pairing mechanisms coexist. PACS numbers: 67.85.-d

Jun 17, 20250 citations

Competition between pairing and tripling in one-dimensional fermions with coexistent s - and p -wave interactions

Yixin Guo, Hiroyuki Tajima

We theoretically investigate in-medium two- and three-body correlations in one-dimensional two-component Fermi gases with coexistent even-parity $s$ -wave and odd-parity $p$ -wave interactions. We find the solutions of the stable in-medium three-body cluster states such as the Cooper triple by solving the corresponding in-medium variational equations. We further feature a phase diagram consisting of the $s$ - and $p$ -wave Cooper pairing phases, and Cooper tripling phase, in a plane of $s$ - and $p$ -wave pairing strengths. The Cooper tripling phase dominates over the pairing phases when both $s$ - and $p$ -wave interactions are moderately strong.We theoretically investigate in-medium two- and three-body correlations in one-dimensional two-component Fermi gases with coexistent even-parity $s$-wave and odd-parity $p$-wave interactions. We find the solutions of the stable in-medium three-body cluster states such as the Cooper triple by solving the corresponding in-medium variational equations. We further feature a phase diagram consisting of the $s$- and $p$-wave Cooper pairing phases, and Cooper tripling phase, in a plane of $s$- and $p$-wave pairing strengths. The Cooper tripling phase dominates over the pairing phases when both $s$- and $p$-wave interactions are moderately strong.

arXiv:2210.07042Physical review. B./Physical review. BJan 31, 20237 citations

Asymmetric fermion superfluid with inter- and intra-species pairings

Xu-Guang Huang, Xuewen Hao, Pengfei Zhuang

arXiv:cond-mat/0610610New Journal of PhysicsOct 19, 20077 citations

Mean-field phase diagram of the Bose-Fermi Hubbard model

Marin Bukov, Lode Pollet

We analyze the ground-state properties of mixtures consisting of scalar bosons and spin- $\frac{1}{2}$ fermions using a mean-field treatment of the local boson-fermion interaction on a simple cubic lattice. In the deep superfluid limit of the boson sector and the BCS regime of the fermion sector, we derive BCS-type equations to determine the phase diagram of the system. We find a competition between a charge density wave and a superconducting phase. In the opposite limit, we study the Mott-insulator-to-superfluid transition of the boson sector in the presence of a staggered density-induced alternating potential provided by the fermions, and determine the mean-field transition line. In the two-superfluids phase of the mixture, we restrict to nearest-neighbor-induced interactions between the fermions and consider the extended Hubbard model. We perform a mean-field analysis of the critical temperature for the formation of boson-assisted $s$ -, extended ${s}^{\ensuremath{-}}$-, $d$ -, and $p$ -wave pairs at fermionic half-filling. We compare our results with a recent dynamical mean-field study [P. Anders et al., Phys. Rev. Lett. 109, 206401 (2012)].We analyze the ground-state properties of mixtures consisting of scalar bosons and spin-$\frac{1}{2}$ fermions using a mean-field treatment of the local boson-fermion interaction on a simple cubic lattice. In the deep superfluid limit of the boson sector and the BCS regime of the fermion sector, we derive BCS-type equations to determine the phase diagram of the system. We find a competition between a charge density wave and a superconducting phase. In the opposite limit, we study the Mott-insulator-to-superfluid transition of the boson sector in the presence of a staggered density-induced alternating potential provided by the fermions, and determine the mean-field transition line. In the two-superfluids phase of the mixture, we restrict to nearest-neighbor-induced interactions between the fermions and consider the extended Hubbard model. We perform a mean-field analysis of the critical temperature for the formation of boson-assisted $s$-, extended ${s}^{\ensuremath{-}}$-, $d$-, and $p$-wave pairs at fermionic half-filling. We compare our results with a recent dynamical mean-field study [P. Anders et al., Phys. Rev. Lett. 109, 206401 (2012)].

arXiv:1311.7148Physical Review BMar 4, 201428 citations

PAIRING IN ASYMMETRICAL FERMI SYSTEMS

Khandker Quader, Renyuan Liao

We consider inter- and intra-species pairing interactions in an asymmetrical Fermi system. Using equation of motion method, we obtain coupled mean-field equations for superfluid gap functions and population densities. We construct a phase diagram across BCS-BEC regimes. Due to intra-species correlations, the BCS singlet superfluid state can sustain finite polarizations, P. For larger P, we find phase separations in BCS and BEC regimes. A superfluid phase exists for all P deep in BEC regime. Our results may apply to pairing in ultracold fermions, nuclear and quark matter physics.We consider inter- and intra-species pairing interactions in an asymmetrical Fermi system. Using equation of motion method, we obtain coupled mean-field equations for superfluid gap functions and population densities. We construct a phase diagram across BCS-BEC regimes. Due to intra-species correlations, the BCS singlet superfluid state can sustain finite polarizations, P. For larger P, we find phase separations in BCS and BEC regimes. A superfluid phase exists for all P deep in BEC regime. Our results may apply to pairing in ultracold fermions, nuclear and quark matter physics.

International Journal of Modern Physics BMay 30, 20070 citations

Pairing in asymmetrical Fermi systems with intra- and interspecies correlations

Renyuan Liao, Khandker Quader

We explore ground states of asymmetrical Fermi systems where both inter- $({g}_{o})$ and intra- $({g}_{1})$ species pairing interactions are present. Using the equation of motion method, we obtain coupled mean-field equations for superfluid gap functions and population densities. We construct a phase diagram across BCS-BEC regimes. At low polarizations $P$ , we find stable superfluid phases on BCS and BCS sides of unitarity for ${g}_{1}>{g}_{1}^{c}$ , a critical value, for a given ${g}_{o}$ . For larger $P$ , we find phase separations in both regimes. A superfluid phase exists for all polarizations deep in the BEC regime. Our results should apply to a broad range of Fermi systems.We explore ground states of asymmetrical Fermi systems where both inter- $({g}_{o})$ and intra- $({g}_{1})$ species pairing interactions are present. Using the equation of motion method, we obtain coupled mean-field equations for superfluid gap functions and population densities. We construct a phase diagram across BCS-BEC regimes. At low polarizations $P$, we find stable superfluid phases on BCS and BCS sides of unitarity for ${g}_{1}>{g}_{1}^{c}$, a critical value, for a given ${g}_{o}$. For larger $P$, we find phase separations in both regimes. A superfluid phase exists for all polarizations deep in the BEC regime. Our results should apply to a broad range of Fermi systems.

arXiv:cond-mat/0611421Physical Review BDec 7, 20075 citations

Competition of superfluid phases in low-dimensional spin-

1\over 2

fermions with

s

- and

p

-wave interactions

The ground state of spin-

1\over 2

fermions with contact

s

-wave inter- and

p

-wave intra-species interactions is discussed. Particularly, we formulate the mean field scheme for calculating thermodynamic properties of the system in arbitrary dimension

D<2

Abstract The ground state of spin-

1/2

fermions with contact

s

-wave inter- and

p

-wave intra-species interactions is discussed. Particularly, we formulate the mean field scheme for calculating thermodynamic properties of the system in arbitrary dimension

D<2

and discuss in detail the phase diagram in the 1D case. Except for clean phases with either singlet or triplet Cooper pairings, we have identified two mixed phases (one stable and another metastable) of the one-dimensional two-component fermions where both pairing mechanisms coexist. PACS numbers: 67.85.-d

We theoretically investigate in-medium two- and three-body correlations in one-dimensional two-component Fermi gases with coexistent even-parity

s

-wave and odd-parity

p

-wave interactions. We find the solutions of the stable in-medium three-body cluster states such as the Cooper triple by solving the corresponding in-medium variational equations. We further feature a phase diagram consisting of the

s

- and

p

-wave Cooper pairing phases, and Cooper tripling phase, in a plane of

s

- and

p

-wave pairing strengths. The Cooper tripling phase dominates over the pairing phases when both

s

- and

p

-wave interactions are moderately strong.

We analyze the ground-state properties of mixtures consisting of scalar bosons and spin-

\frac{1}{2}

fermions using a mean-field treatment of the local boson-fermion interaction on a simple cubic lattice. In the deep superfluid limit of the boson sector and the BCS regime of the fermion sector, we derive BCS-type equations to determine the phase diagram of the system. We find a competition between a charge density wave and a superconducting phase. In the opposite limit, we study the Mott-insulator-to-superfluid transition of the boson sector in the presence of a staggered density-induced alternating potential provided by the fermions, and determine the mean-field transition line. In the two-superfluids phase of the mixture, we restrict to nearest-neighbor-induced interactions between the fermions and consider the extended Hubbard model. We perform a mean-field analysis of the critical temperature for the formation of boson-assisted

s

-, extended ${s}^{\ensuremath{-}}$-,

d

-, and

p

-wave pairs at fermionic half-filling. We compare our results with a recent dynamical mean-field study [P. Anders et al., Phys. Rev. Lett. 109, 206401 (2012)].

We explore ground states of asymmetrical Fermi systems where both inter-

({g}_{o})

and intra-

({g}_{1})

species pairing interactions are present. Using the equation of motion method, we obtain coupled mean-field equations for superfluid gap functions and population densities. We construct a phase diagram across BCS-BEC regimes. At low polarizations

P

, we find stable superfluid phases on BCS and BCS sides of unitarity for

{g}_{1}>{g}_{1}^{c}

, a critical value, for a given

{g}_{o}

. For larger

P

, we find phase separations in both regimes. A superfluid phase exists for all polarizations deep in the BEC regime. Our results should apply to a broad range of Fermi systems.