New fluctuation-driven phase transitions and critical phenomena in unconventional superconductors

Dimo I. Uzunov

Home/Archive/arXiv

arXiv · 0704.2287

New fluctuation-driven phase transitions and critical phenomena in unconventional superconductors

Dimo I. Uzunov

View original source ↗Read source document ↗Export metadata ↓

Abstract

Using the renormalization group method, new type of fluctuation-driven first order phase transitions and critical phenomena are predicted for certain classes of ferromagnetic superconductors and superfluids with unconventional (spin-triplet) Cooper pairing. The problem for the quantum phase transitions at extremely low and zero temperatures is also discussed. The results can be applied to a wide class of ferromagnetic superconductive and superfluid systems, in particular, to itinerant ferromagnets as UGe2 and URhGe.

Explore related subjects

cond-mat.supr-con cond-mat.stat-mech

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Dimo I. Uzunov. 2007-04-18. New fluctuation-driven phase transitions and critical phenomena in unconventional superconductors. https://arxiv.org/abs/0704.2287

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Interaction and disorder effects on Cooper instability in two-dimensional fractional Dirac semimetals

Employing a renormalization group analysis that allows for an unbiased treatment of competing physical ingredients, we systematically trace how the interplay between Cooper pairing and disorder scatterings governs the emergence or suppression of Cooper instability in the low-energy regime of fractional Dirac semimetals.In the clean limit, we find that the emergence of Cooper instability requires surpassing a finite interaction threshold $|λ_c|$, and depends sensitively on both the fractional exponent $α$ and the transfer momentum $\mathbf{Q}=(Q,ϕ)$. Specifically, bigger values of $α$ enhance the tendency toward BCS instability. For $α\in(0.001,0.61)$, the $(Q,ϕ)$ parameter space separates into two distinct regions: Zone-\uppercase\expandafter{\romannumeral1}, where Cooper instability is suppressed, and Zone-\uppercase\expandafter{\romannumeral2}, where it is allowed. In the presence of disorders, we demonstrate that they can either promote or suppress Cooper instability. Disorder of type $Δ_1$ or $Δ_2$ enhances superconductivity by reducing the critical interaction threshold $|λ_c|$ and expanding the superconducting phase space (Zone-\uppercase\expandafter{\romannumeral2}). In sharp contrast, either $Δ_0$ or $Δ_3$ suppresses Cooper pairing by increasing $|λ_c|$ and shrinking the available phase space (Zone-\uppercase\expandafter{\romannumeral1}). Although Cooper instability can be enhanced when promotive disorders ($Δ_1$, $Δ_2$) coexist with a single suppressive disorder ($Δ_0$ or $Δ_3$), the suppressive influence of $Δ_{0,3}$ generally dominates the promotive effects of $Δ_{1,2}$ in the presence of all sorts of disorders. These results would be helpful for further studies of fractional Dirac semimetals and alike materials.

cond-mat.supr-con↗

arXiv2026

Electrochemical Growth of Full Volume Meissner Effect Superconducting BKBO

In this work we show the results of electrochemical synthesis of BKBO crystals using three different experimental setup configurations. The setups differ between each other by varying level of control over physical variables and progressing from a two-electrode to a three-electrode configuration using highly oriented platinum counter electrode. By systematic analysis of the temperature dependence of the magnetic susceptibility at the superconducting transition of the collected crystals we observe that an order of magnitude sharper superconducting transition is achieved for the most comprehensive three-electrode setup. In addition, the level of chemical substitution can be controlled by the value of the overpotential versus reference electrode. We demonstrate that with this technique a full volume Meissner effect can be achieved with a sharp transition temperature for the superconducting crystal.

cond-mat.supr-con↗

arXiv2026

Topological Superconducting Phases in a Strained Altermagnet-Superconductor Heterostructure

We investigate topological superconductivity in a heterostructure consisting of a two-dimensional $s$-wave superconductor and a $d$-wave altermagnet with Rashba spin-orbit coupling. In particular, we study the effects of strain and hopping anisotropy on the topological superconducting phases. By calculating the Chern number, we obtain topological phase diagrams as functions of the chemical potential and the strength of the effective magnetic field induced by the magnetic proximity effect. We find that strain-induced lattice distortion allows topological superconducting phases to emerge over a broad parameter region. Our findings suggest that strain that lowers symmetry can serve as a route to realizing topological superconductivity in altermagnet-superconductor heterostructures.

cond-mat.supr-con↗