scholarly journals Vortex phase diagram and the normal state of cuprates with charge and spin orders

2020 ◽  
Vol 6 (7) ◽  
pp. eaay8946 ◽  
Author(s):  
Zhenzhong Shi ◽  
P. G. Baity ◽  
T. Sasagawa ◽  
Dragana Popović
Keyword(s):  
Phase Diagram ◽  
Normal State ◽  
Ground State ◽  
High Field ◽  
High Temperature Superconductors ◽  
Upper Critical Field ◽  
Energy Scale ◽  
Zero Field ◽  
Vortex Matter ◽  
Nonlinear Transport

The phase diagram of underdoped cuprates in a magnetic field (H) is key to understanding the anomalous normal state of these high-temperature superconductors. However, the upper critical field (Hc2), the extent of superconducting (SC) phase with vortices, and the role of charge orders at high H remain controversial. Here we study stripe-ordered La-214, i.e., cuprates in which charge orders are most pronounced and zero-field SC transition temperatures Tc0 are lowest. This enables us to explore the vortex phases in a previously inaccessible energy scale window. By combining linear and nonlinear transport techniques sensitive to vortex matter, we determine the T − H phase diagram, directly detect Hc2, and reveal novel properties of the high-field ground state. Our results demonstrate that quantum fluctuations and disorder play a key role as T → 0, while the high-field ground state is likely a metal, not an insulator, due to the presence of stripes.

scholarly journals Ground state and stability of the fractional plateau phase in metallic Shastry–Sutherland system TmB4

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matúš Orendáč ◽  
Slavomír Gabáni ◽  
Pavol Farkašovský ◽  
Emil Gažo ◽  
Jozef Kačmarčík ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Ground State ◽  
Constant Magnetic Field ◽  
Paramagnetic Phase ◽  
The Other ◽  
Zero Field ◽  
Plateau Phase ◽  
Low Field ◽  
Zero Field Cooling

AbstractWe present a study of the ground state and stability of the fractional plateau phase (FPP) with M/Msat = 1/8 in the metallic Shastry–Sutherland system TmB4. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin. In this case the FPP states are closely associated with the half plateau phase (HPP, M/Msat = ½), mediate the HPP to the low-field antiferromagnetic (AF) phase and depend on the thermodynamic history. Thus, in the same place of the phase diagram both, the stable and the metastable (dynamic) fractional plateau (FP) states, can be observed, depending on the way they are reached. In case of metastable FP states thermodynamic paths are identified that lead to very flat fractional plateaus in the FPP. Moreover, with a further decrease of magnetic field also the low-field AF phase becomes influenced and exhibits a plateau of the order of 1/1000 Msat.

scholarly journals Ideal charge-density-wave order in the high-field state of superconducting YBCO

2016 ◽  
Vol 113 (51) ◽  
pp. 14645-14650 ◽  
Author(s):  
H. Jang ◽  
W.-S. Lee ◽  
H. Nojiri ◽  
S. Matsuzawa ◽  
H. Yasumura ◽  
...  
Keyword(s):  
Charge Density ◽  
Critical Field ◽  
Ground State ◽  
Charge Density Wave ◽  
High Field ◽  
Cuprate Superconductors ◽  
Density Wave ◽  
Quantum Oscillation ◽  
Zero Field ◽  
Correlation Volume

The existence of charge-density-wave (CDW) correlations in cuprate superconductors has now been established. However, the nature of the CDW ground state has remained uncertain because disorder and the presence of superconductivity typically limit the CDW correlation lengths to only a dozen unit cells or less. Here we explore the field-induced 3D CDW correlations in extremely pure detwinned crystals of YBa2Cu3O2(YBCO) ortho-II and ortho-VIII at magnetic fields in excess of the resistive upper critical field (Hc2) where superconductivity is heavily suppressed. We observe that the 3D CDW is unidirectional and possesses a long in-plane correlation length as well as significant correlations between neighboring CuO2planes. It is significant that we observe only a single sharply defined transition at a critical field proportional toHc2, given that the field range used in this investigation overlaps with other high-field experiments including quantum oscillation measurements. The correlation volume is at least two to three orders of magnitude larger than that of the zero-field CDW. This is by far the largest CDW correlation volume observed in any cuprate crystal and so is presumably representative of the high-field ground state of an “ideal” disorder-free cuprate.

HIGH-FIELD MAGNETOTRANSPORT OF EPITAXIAL LA2-XSRXCUO4 THIN FILMS IN THE REGIME OF LOW SR-DOPING

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3747-3752
Author(s):  
L. WECKHUYSEN ◽  
J. VANACKEN ◽  
P. WAGNER ◽  
K.-Q. RUAN ◽  
I. GORDON ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Diagram ◽  
High Field ◽  
High Temperature Superconductors ◽  
Superconducting Gap ◽  
Pulsed Magnetic Fields ◽  
Logarithmic Divergence ◽  
Metallic Behavior ◽  
Spin Gap ◽  
Substitution Ratio

High temperature superconductors have an unusual temperature (T) — doping (x) phase diagram, in which both antiferromagnetism and superconductivity occur. The spin gap and the superconducting gap are the two essential features of the T(x) plane which evolve with doping. A material allowing investigating the T-x plane in detail, from the underdoped (x<0.15) to the overdoped (x>0.15) regime, is the La 2- x Sr x CuO 4 superconductor. The temperature dependence of the resistivity strongly depends on the substitution ratio x. Overdoped films show metallic behavior, meaning that ρ(T) is linear above 100 K, while it saturates for lower temperatures. This saturation persists below Tc, when superconductivity is suppressed by sufficiently high pulsed magnetic fields. From the slightly overdoped (0.2<x) down to the strongly underdoped regime (x~0.03) we observe, instead of saturation, a ρ(T) dependence with logarithmic divergence in the field-induced normal state at T→0. For underdoped films (x<0.1) a superlinear ρ(T) behavior develops at intermediate temperatures (50 K <T<200 K ), indicating the opening of the spin gap.

scholarly journals Hole pocket–driven superconductivity and its universal features in the electron-doped cuprates

2019 ◽  
Vol 5 (2) ◽  
pp. eaap7349 ◽  
Author(s):  
Yangmu Li ◽  
W. Tabis ◽  
Y. Tang ◽  
G. Yu ◽  
J. Jaroszynski ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Transition Temperature ◽  
Normal State ◽  
Superconducting State ◽  
Upper Critical Field ◽  
Superfluid Density ◽  
Superconducting Transition ◽  
Research Attention ◽  
Quantum Oscillations ◽  
Hole Pocket

After three decades of intensive research attention, the emergence of superconductivity in cuprates remains an unsolved puzzle. One major challenge has been to arrive at a satisfactory understanding of the unusual metallic “normal state” from which the superconducting state emerges upon cooling. A second challenge has been to achieve a unified understanding of hole- and electron-doped compounds. Here, we report detailed magnetoresistance measurements for the archetypal electron-doped cuprate Nd2−xCexCuO4+δthat, in combination with previous data, provide crucial links between the normal and superconducting states and between the electron- and hole-doped parts of the phase diagram. The characteristics of the normal state (magnetoresistance, quantum oscillations, and Hall coefficient) and those of the superconducting state (superfluid density and upper critical field) consistently indicate two-band (electron and hole) features and point to hole pocket–driven superconductivity in these nominally electron-doped materials. We show that the approximate Uemura scaling between the superconducting transition temperature and the superfluid density found for hole-doped cuprates also holds for the small hole component of the superfluid density in electron-doped cuprates.

Evolution of vortex matter, phase diagram and upper critical field in the FeSe1-xSx system

2020 ◽  
Author(s):  
Vladimir Vlasenko ◽  
ANDREY SADAKOV ◽  
Taisiya Romanova ◽  
Sergey Gavrilkin ◽  
Alexey Dik ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Critical Field ◽  
Upper Critical Field ◽  
Vortex Matter ◽  
Matter Phase

scholarly journals Magnetic field reveals vanishing Hall response in the normal state of stripe-ordered cuprates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhenzhong Shi ◽  
P. G. Baity ◽  
J. Terzic ◽  
Bal K. Pokharel ◽  
T. Sasagawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hall Coefficient ◽  
Normal State ◽  
High Field ◽  
Fundamental Property ◽  
Zero Field ◽  
Superconducting Transition ◽  
Underdoped Cuprates ◽  
Competing Orders

AbstractThe origin of the weak insulating behavior of the resistivity, i.e. $${\rho }_{xx}\propto {\mathrm{ln}}\,(1/T)$$ ρ x x ∝ ln ( 1 / T ) , revealed when magnetic fields (H) suppress superconductivity in underdoped cuprates has been a longtime mystery. Surprisingly, the high-field behavior of the resistivity observed recently in charge- and spin-stripe-ordered La-214 cuprates suggests a metallic, as opposed to insulating, high-field normal state. Here we report the vanishing of the Hall coefficient in this field-revealed normal state for all $$T\ <\ (2-6){T}_{{\rm{c}}}^{0}$$ T < ( 2 − 6 ) T c 0 , where $${T}_{{\rm{c}}}^{0}$$ T c 0 is the zero-field superconducting transition temperature. Our measurements demonstrate that this is a robust fundamental property of the normal state of cuprates with intertwined orders, exhibited in the previously unexplored regime of T and H. The behavior of the high-field Hall coefficient is fundamentally different from that in other cuprates such as YBa2Cu3O6+x and YBa2Cu4O8, and may imply an approximate particle-hole symmetry that is unique to stripe-ordered cuprates. Our results highlight the important role of the competing orders in determining the normal state of cuprates.

LOW-TEMPERATURE NORMAL-STATE HALL EFFECT IN HIGH-TcBi2Sr2-xLaxCuO6+δ REVEALED BY 60 T MAGNETIC FIELDS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3171-3174
Author(s):  
F. F. BALAKIREV ◽  
J. B. BETTS ◽  
G. S. BOEBINGER ◽  
S. ONO ◽  
Y. ANDO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Normal State ◽  
Ground State ◽  
Low Temperatures ◽  
Optimal Doping ◽  
Underdoped Sample ◽  
Additional Support

We report low-temperature Hall coefficient in the normal state of the high-Tc superconductor Bi 2 Sr 2-x La x CuO 6+δ. The Hall coefficient was measured down to 0.5 K by suppressing superconductivity with a 60 T pulsed magnetic field. The carrier concentration was varied from overdoped to underdoped regimes by partially substituting Sr with La in a set of five samples. The observed saturation of the Hall coefficient at low temperatures suggests the ability to extract the carrier concentration of each sample. The most underdoped sample exhibits a diverging Hall coefficient at low temperatures, consistent with a depletion of carriers in the insulating ground state. The Hall number exhibits a sharp peak providing additional support for the existence of a phase boundary at the optimal doping.

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