Published: Jan. 1, 2024
Recently Sun et al. (Nature621, 493 (2023)) reported on the discovery of high-temperature superconductivity in highly compressed La3Ni2O7-δ. Besides ongoing studies phase structural transition, pairing mechanism, and physical properties La3Ni2O7-d, here we explored a possibility for electron-phonon mechanism this compound. To do this, analyzed experimental data temperature dependent resistance, R(T), extracted pressure Debye temperature, ΘD(P), with an approximate value ΘD(25 GPa) = 550 K. From established that La3Ni2O7-d is strong-coupled superconductor coupling constant λe-ph(P=22.4 1.75. This deduced close to λe-ph 1.70 ambient superconductors Nb3R (R Sn, Al), it significantly lower than 2.4 β-pyrochlore oxide KOs2O6 superconductor. As part exploration determined level microcrystalline strain, 0.008 ≤ ε(P) 0.011, high-pressure Fmmm-phase, < low-pressure Amam-phase. Based our analysis, proposed probable condition observe zero-resistance state
Language: Английский
Citations
4Primary superconducting parameters of highly compressed nonclathrate ternary hydride LaB2H8
Published: Jan. 1, 2025
Language: Английский
Citations
0Charge ordering as the driving mechanism for superconductivity in rare-earth nickel oxides
Physical Review Materials, Journal Year: 2024, Volume and Issue: 8(6)
Published: June 4, 2024
Superconductivity is one of the most intriguing properties matter, described by an attractive interaction that binds electrons into Cooper pairs. To date, highest critical temperature at ambient conditions achieved in copper oxides. While layered nickel oxides were long proposed to be analogous cuprates, superconductivity was only demonstrated 2019 albeit without clarifying pairing mechanism. Here we use density functional theory show nickelates driven electron-phonon coupling originating from a charge ordering. Due intrinsic electronic instability half-doped compounds, $\mathrm{N}{\mathrm{i}}^{1.5+}$ cations dismutate more stable $\mathrm{N}{\mathrm{i}}^{+}$ and $\mathrm{N}{\mathrm{i}}^{2+}$ cations, which accompanied bond disproportionation $\mathrm{Ni}{\mathrm{O}}_{4}$ complexes producing insulating charge-ordered state. Once doping suppresses instability, vibration sufficient reproduce key characteristic observed experimentally, notably dome ${T}_{c}$ as function content. These phenomena are identified if relevant degrees freedom well exchange-correlation sufficiently amends self-interaction errors involved simulations. Finally, despite presence correlation effects inherent $3d$ elements favor formation local Ni spins, mechanism behind pairs nickelate superconductors appears similar nonmagnetic bismuth oxide superconductors.
Language: Английский
Citations
3Evidences for d-wave symmetry of c-axis superconducting gap in atomically thin twisted flakes of bismuth-based HTS cuprates
Physica C Superconductivity, Journal Year: 2024, Volume and Issue: 623, P. 1354549 - 1354549
Published: June 24, 2024
Language: Английский
Citations
3A-15 type superconducting hydride La4H23: Nanograined structure with low strain, strong electron-phonon interaction, and moderate level of nonadiabaticity
Superconductor Science and Technology, Journal Year: 2024, Volume and Issue: 37(9), P. 095016 - 095016
Published: Aug. 14, 2024
Abstract
For
seven
decades,
when
referring
to
A-15
superconductors,
we
meant
metallic
A
3
B
alloys
(where
is
a
transition
metal,
and
group
IIIB
IVB
elements)
discovered
by
Hardy
Hulm
(1953
Phys.
Rev.
89
884).
Nb
Ge
exhibited
the
highest
superconducting
temperature,
T
c
=
23K,
among
these
alloys.
One
of
alloys,
Sn,
primary
material
in
modern
applied
superconductivity.
Recently,
Guo
et
al
(2024
Natl
Sci.
nwae149,
https://doi.org/10.1093/nsr/nwae149
)
extended
family
superconductors
where
ions
are
arranged
beta
tungsten
(A-15)
sublattice
observation
,zero
81K
La
4
H
23
phase
compressed
at
P
118
GPa.
Despite
fact
that
has
much
lower
comparison
with
near-room-temperature
LaH
10
(
250K
∼
200
GPa)
Drozdov
(2019
Nature
569
531),
holds
record
for
within
family.
Cross
109
L020503)
confirmed
high-temperature
superconductivity
.
In
this
paper,
analyzed
available
experimental
data
measured
found
superconductor
exhibits
nanograined
structure,
5.5
nm
⩽
D
35
nm,
low
crystalline
strain,
Language: Английский
Citations
2Electron-phonon mediated superconductivity in
Physical review. B./Physical review. B, Journal Year: 2024, Volume and Issue: 110(23)
Published: Dec. 2, 2024
Nickel oxide superconductors offer an alternative playground for understanding the formation of Cooper pairs in correlated materials such as famous cuprates. By studying $\mathrm{L}{\mathrm{a}}_{n+1}\mathrm{N}{\mathrm{i}}_{n}{\mathrm{O}}_{2n+2}$ phase diagram on basis hybrid and spin-polarized density functional theory simulations, we reveal existence charge bond ordered (CBO) insulating phases that are quenched by doping effects, ultimately resulting a metallic at $n=5$ member. Nevertheless, phonons associated with CBO identified remain sufficiently large to mediate $\mathrm{L}{\mathrm{a}}_{6}\mathrm{N}{\mathrm{i}}_{5}{\mathrm{O}}_{12}$, yielding computed critical temperature between ${T}_{c}=11$ 19 K consistent 13 observed experimentally $\mathrm{N}{\mathrm{d}}_{6}\mathrm{N}{\mathrm{i}}_{5}{\mathrm{O}}_{12}$. Hence, electron-phonon mechanism cannot be ruled out nickelates. Finally, order identify superconducting mechanism, extracting relevant instabilities appears critical.
Language: Английский
Citations
1Solving mystery with the Meissner state in La3Ni2O7-x
Published: June 25, 2024
Recently, zero resistance state in highly compressed La3Ni2O7-x has reported by Zhang et al (Nature Physics (2024), 10.1038/s41567-024-02515-y). However, all attempts of many research groups to detect the Meissner La3Ni2O7- have been failed. To explain this puzzle, an exotic superconducting (so-called, filamentary superconductivity) proposed (Zhou al, arXiv:2311.12361). Here, we extracted temperature dependent self-field critical current, Ic(sf,T), dataset from current-voltage curves (2024)). The analysis Ic(sf,T) reveals that exhibits d-wave superconductivity with gap-to-transition ratio 2Δ(0)/(k_B T_c )=4.0±0.3, and a very large ground London penetration depth, lambda(0, P=16.6 GPa) = 6.0 micron, high Ginzburg-Landau parameter k(0, 1500. This implies lower field Bc1(0, 34 microTesla is same order as Earth's magnetic field. Based on this, represents challenging task. I can hypothesize flux trap effect recently Minkov 19, 1293 (2023)) eliminate diamond anvil cell (DAC) background signal experiments properties hydrides be also applied studies superconductor.
Language: Английский
Citations
0Solving Mystery with the Meissner State in La3ni2o7-Δ
Published: Jan. 1, 2024
Language: Английский
Citations
0Solving mystery with the Meissner state in La3Ni2O7-δ
Published: Jan. 1, 2024
Language: Английский
Citations
0