To submit a proposal for magnet time, …...Nature 424, 912 (2003)Signature of Optimal Doping in...
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To submit a proposal for magnet time, www.magnet.fsu.edu
Nature 424, 912 (2003)Signature of Optimal Doping in Hall-effect Measurements on a High-Temperature Superconductor
010203040
T [K
]
p (hole concentration per Cu)0.160.100
Metal
Bi2Sr2-xLaxCuO 6+ δ
Strong Insulator
Phys. Rev. Lett. 85, 638 (2000)Metal-to-Insulator Crossover in the Low-TemperatureNormal State of Bi2Sr2–xLaxCuO6+δ
Phys Rev Lett 77, 5417 (1996) Insulator-to-metal crossover in the normal state of La2-xSrxCuO4 near optimum doping
010203040
T [K
]
0.160 0.055Metal
StrongInsulator Log-T Insulator
La2-xSr xCuO4
p (hole concentration per Cu)
The Abnormal Normal State of the High-Tc SuperconductorsUsing 60 teslas ...
...to suppress the superconducting state
...(undress the electrons)……to reveal the low-temperature
normal-state phase diagram
National High Magnetic Field Laboratory
Florida State University
33T Florida Bitter Magnet
45T Hybrid Magnet
65T Pulse Magnet15mm bore
Los Alamos National Laboratory
Advanced MagneticResonance Imagingand Spectroscopy Facility
University of Florida
11.4T MRI Magnet400mm warm bore
High B/T Facility17T, 6wks at 1mK
In-house Scientists:Luis Balicas (Magnetism and Transport)Lloyd Engel (Microwave conductivity)Scott Hannahs (Transport, Data Acquisition)Phil Kuhns (Condensed Matter NMR)Tim Murphy (Low Temp. Physics)Eric Palm (Low Temperature Physics)
Arneil Reyes (Condensed Matter NMR)Dmitri Smirnov (FIR & Raman Spectroscopy)Alexei Souslov (Ultrasound Spectroscopy)Stan Tozer (High Pressure)Yong-Jie Wang (Far Infrared Spectroscopy)Xing Wei (Visible Optical Spectroscopy)Sergei Zvyagin (Sub/Millimeter Wave Spectroscopy)
NHMFL –DC Facility
Imaging the Vortex Lattice in High Tc Superconductor
V. Mitrovic, et al. Nature (2001)
Aharonov Bohm Phase in Carbon Nanotubes
S. Zaric, et al. Science (2004)
In-house Scientists:Scott Crooker (Visible, IR, THz Spectroscopy)Marcelo Jaime (Thermodynamics, esp. Specific Heat)Neil Harrison (Thermodynamics, esp. Magnetization)Fedor Balakirev (Magneto-transport)John Singleton (Magnetization, GHz spectroscopy)Charles Mielke (RF Transport & Head of Users Program)Albert Migliori (Thermodynamics, Ultrasound Spectroscopy)Dwight Rickel (Optical Spectroscopy)Jason Lashley (Thermodynamics, esp. Specific Heat)
NHMFL –Pulsed Facility
Six fully-multiplexed magnet cells host 150-200 visiting scientists a year,
20% travel from overseas to use unique pulsed field capabilities
Magnetic Field Driven Phase Transitions and Quantum Criticality
Jaime, et al, PRL 89 (2002) 287201Harrison, et al, PRL 90 (2003) 096402 Kim, et al, PRL 91 (2003) 256401
Preliminary, unpublished data removed by request of author.
High B/T Facility
In-house Scientists:Jian-Sheng Xia (Low T Physics)Dwight Adams (Low T Physics)Yoonseok Lee (Cond. Matt. Physics)
NHMFL - UF Facilities
•High Field:B = 15.5/17 T– 4.2/2.2 K
•Ultra-Low Temperatures5 mole PrNi5 nuclear demag refrigeratorTmin< 0.5mK, 8nW cooling powerMaintains 1mK for > 6 wks
AMRIS Facility
Rxx (Ω
)2+3/8
7/38/3
7/3
8/3
12/514/5
Need for High B/T• Small energy gap of FQHE states• Small energy differences among
competing quantum phases• Quantum phase transitions
Nuclear MagneticOrdering
Hybrid Insert InnovationsMid-plane disks
use elongated hole to maximize hoop strength.
End disks use elliptical holes to increase bending stiffness.
Mid-Plane / End TurnFlorida Bitter Plates
Cu/Nb3Sn composite strands around Cu cores inside
10mm x 12mm steel conduit45T NHMFL hybrid magnet
Superconducting Magnet Development
900 MHz NMR magnet• 21.1 teslas• 105mm warm bore• 1 ppb homogeneity
High Tc Insert Coil• 1999…3T…16mm bore
in 19T background field• 2003…5T…38mm bore
in 20T background field
NHMFL: Justin Schwartz, Huub Weijers, Ulf TrociewitzIndustrial Collaborator: Ken Marken, Oxford Instruments
A-section(double pancake)
B-section(double pancake)
C-section(layer wound)
Sectionsconnected in series
Terminals
1 mm gapbetween sections
for LHe flow
Bi2212 conductorco-wound with
oxide coated ss-tape
Coil stacks andjoints gluedwith epoxy
100 YEARS OF NON-DESTRUCTIVE MAGNETSM
AG
NE
TIC
FIE
LD
(t
esla
s)
YEAR
2003: 25T in 38mm boreusing 5T high-Tc insert(world record)
2004: 900 MHz (21.1T) NMR magnet(competitive in peak field,uniquely large 105mm warm bore)
1996: 33T DC Resistive Magnet (world record)
1999: 80T Short-Pulse Magnet (ties the world record)
2006 - 100T Multi-shot Pulsed Magnet
1998: 60T Controlled-Pulse Magnet(world record) (rebuild in 2004)
1999: 45T DC Hybrid Magnet(world record)
State-of-the-Art Fermi Surface Studies Sample-Tilting in the Hybrid… or deHaas-vanAlphen Oscillations
in Pulsed Magnetic Fields
30 35 40 45 50 55 60-10
-5
0
5
10
dHvA in Ce0.6La0.4B6si
gnal
(a.u
.)
B (T)
Goodrich et al, PRL (2001), for example
sampledetection coil
compensation
1mm diametMost suitable for:
Heavy mass systemsDisordered systems
Most suitable forlow-dimensional systems
Hussey et al, Nature (2003)“Full Three-Dimensional Mapping of the Fermi Surface in a High-Tc Superconductor: Tl2Ba2CuO6+δ (Tc = 20K)”
0
0.01
0.02
0.03
0.04
0.05
0.06
-90 0 90
ρ c (Ωcm
)
θ (degrees)
H//ab H//c H//ab
0
0.05
0.1
0.15
0 100 200 300
ρ c (Ωcm
)
T (K)
φ
0o
20o
28o
36o
44o
Tl2Ba
2CuO
6+δ
T = 4.2KH = 45 T
Test for interlayer coherence in a quasi-two-dimensional superconductor
Quasi-2D Fermi Surface ofκ-(BEDT-TTF)2Cu(NCS)2. The lines indicate quasiparticle orbits on the Fermi Surface due to the in-plane magnetic field B. Note the closed orbits about the "belly" of the Fermi Surface.
John Singleton, P. A. Goddard, A. Ardavan, N. Harrison, S. J. Blundell, J. A. Schlueter, and A. M. KiniPhys. Rev. Lett. 88, 037001 (2002) “Test for interlayer coherence in a quasi-two-dimensional superconductor”
BaCuSi2O6: An ancient pigmentA quasi-2D magnetic insulatorGapped spin dimer ground state
2 cm
Magnetic fields drive a phase transitionto a gas of bosonic spin triplet excitations (triplons)
Nature 424, 912 (2003)Signature of Optimal Doping in Hall-effect Measurements on a High-Temperature Superconductor
010203040
T [K
]
p (hole concentration per Cu)0.160.100
Metal
Bi2Sr2-xLaxCuO 6+ δ
Strong Insulator
Phys. Rev. Lett. 85, 638 (2000)Metal-to-Insulator Crossover in the Low-TemperatureNormal State of Bi2Sr2–xLaxCuO6+δ
Phys Rev Lett 77, 5417 (1996) Insulator-to-metal crossover in the normal state of La2-xSrxCuO4 near optimum doping
010203040
T [K
]
0.160 0.055Metal
StrongInsulator Log-T Insulator
La2-xSr xCuO4
p (hole concentration per Cu)
The Abnormal Normal State of the High-Tc SuperconductorsUsing 60 teslas ...
...to suppress the superconducting state
...(undress the electrons)……to reveal the low-temperature
normal-state phase diagram
The Abnormal Normal State of the High-Tc SuperconductorsUsing 60 teslas ...
...to suppress the superconducting state
...(undress the electrons)……to reveal the low-temperature
normal-state phase diagram
The Cast of Characters
Joze Bevk, Al PassnerBell Laboratories
Fedor Balakirev, Jon Betts, Neil Harrison, Kee Hoon Kim, Albert MiglioriNational Magnetic Field Laboratory at Los Alamos
BSLCOYoichi Ando, Shimpei Ono, S. Komiya, Kouji Segawa
CRIEPI, Tokyo LSCOKohji Kishio, Masayuki Okuya, Tsuyoshi Kimura,
Jun-ichi Shimoyama, University of TokyoLSCO and Ladder CompoundShin-ichi Uchida, Naoki Motoyama, Kenji Tamasaku,
Noriya Ichikawa, Hiroshi Eisaki, University of TokyoTl-2201Andre Tyler, Andy Mackenzie
Cambridge University and University of St. Andrews Bi-2201Nan Lin Wang, Christoph Geibel, Frank SteglichTH Darmstadt and Max Planck Institute, Dresden
Bi2Sr2-xLaxCuO6+δ
PHASE TRANSITION LINE
PHASE C(superconductivity)
PHASE A(magnetism)
PHASE B(ordinary metal)
MAGNETIC FIELD or PRESSUREor DOPING (carrier concentration)
TEMPER
ATU
RE
STRANGE BEHAVIOR
G. R. Stewart, Rev. Mod. Phys. 73, 797 (2001)
A. Suslov et al., Phys. Rev. B68, 20406-1-4 (2003).P. Chandra et al., Nature 417, 831 (2002).M. Jaime et al., PRL 89, 287201 (2002).N. Harrison et al., PRL 90, 096402 (2003).K.H. Kim et al., PRL to be published (2004).
Tuning to Quantum Critical Pointsusing Pressure or Magnetic Field
The Abnormal Normal State of the High-Tc Superconductors
pseudogap
Anderson, Science 256, 1526 (1992) and Research News, Science 278, 1879 (1997)
Using 60 teslas....to suppress the superconducting state and reveal the normal-state phase diagram
Challenges in Producing High Magnetic Fields
Pressure Under Water 12 feet Ears 6 pounds per square inch
2000 feet Submarine 1000 psi12,000 feet Ocean Floor 6000 psi
Pressure inside NHMFL Pulsed Magnets 800,000 gauss Pulsed Magnet 200,000 psi
(which equals 1.4GPa or 130 kg per square millimeter)(which is more pressure than most materials can handle)
Strong Electromagnets
Generate BIG Forces
The Niobium ribbons work(sort of)
like steel bars in cement…
…except the nano-compositeis stronger than either constituent
20% Niobium Dropletsin 80% Copper Matrix
The diameterof a Human hair
20 times larger magnification
Pulse 915July 28,2000
Analysis of Debrisuntil January 2001
9:15:01 am
9:15:00 am
Until You Spread Your Wings,You’ll Have No Idea How Far You Can Walk.
The Abnormal Normal State of the High-Tc Superconductors
pseudogap
Anderson, Science 256, 1526 (1992) and Research News, Science 278, 1879 (1997)
Using 60 teslas....to suppress the superconducting state and reveal the normal-state phase diagram
PRL 77, 5417 (1996)
0
0.5
1
1.5
0 50 100 150 200 250 300
ρab
[mΩ
cm]
T [K]
x = 0.84
0.76
0.73
0.66
0.39
0.23
Und
erdo
ped
Opt
imum
Ove
rdop
ed
PRL 85, 638 (2000)
BSLCO single crystalsab - plane
La1.92 Sr0.08 CuO4
PRL 75, 4662 (1995)
0.1 1 10 1000.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
BSLCO
Bi-2201 kFl =1 @ 3.1 mΩ
0.39
0.66
0.73
0.76
BSLCO y=0.84
ρab
BSL
CO (m
Ω c
m)
DocumentsData
La2-xSrxCuO4 and Bi2Sr2-yLayCuO6+δ In-Plane Resistivity
T(K)
Logarithmic Divergence of the In-Plane Resistivityof Underdoped Bi2Sr2-xLaxCuO6+δ
0.1 1 10 100
1
0.9
0.8
underdoped BSLCO
kFl =1 @ 3.1 mΩ-cm
2
BSLCO y=0.84
ρab
BSL
CO (m
Ω c
m)
Bi2Sr1.16La0.84CuO6+δ In-Plane Resistivity
T(K)
Bi2Sr2-xLaxCuO6+δ
Bi2Sr2-xLaxCuO6+δ
Phys. Rev. Lett. 85, 638 (2000)Metal-to-Insulator Crossover in the Low-TemperatureNormal State of Bi2Sr2–xLaxCuO6+δ
Logarithmically Divergent Resistivity in Underdoped Cuprates
0.2
0.3
0.4
1 10
r ab[m
Wcm
]
T [K]
x = 0.73
x = 0.66
kFl =15
0.1 1 10 1000.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
BSLCO
Bi-2201 kFl =1 @ 3.1 mΩ
0.39
0.66
0.73
0.76
BSLCO y=0.84
ρab
BSL
CO (m
Ω c
m)
DocumentsData
La2-xSrxCuO4 and Bi2Sr2-yLayCuO6+δ In-Plane Resistivity
T(K)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
LSCO
0.22
0.17
0.15
LSCOx=0.08
LSCO kFl =1 @ 1.6 mΩ
ρab
LSC
O (m
Ω c
m)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
LSCO
0.22
0.17
0.15
LSCOx=0.08
LSCO kFl =1 @ 1.6 mΩ
ρab
LSC
O (m
Ω c
m)
kFl ~ 15
Similarities between the Insulator-to-Metal crossover in BSLCO and LSCO:--- occurs under the superconducting ‘dome’--- occurs at the same normalized resistivity, at kFl ~15.--- the Insulator exhibits Log-T divergence.
ρab /cο = h/(e2kFl)
QUANTUM CRITICAL POINTin the HIGH-Tc CUPRATES ?
--- In the quantum critical region, temperature is the only energy scale controlling the physics.
--- Strong critical fluctuations can mediate singular interactions between quasiparticles.
--- These singular interactions can provide both a strong pairing mechanism and a source of non-Fermi liquid behavior.
--- The observed linear-T resistivity is attributed to Quantum Critical Behavior
from “Universal Quantum-Critical Dynamics of Two-Dimensional Antiferromagnets”Subir Sachdev and Jinwu Ye, PRL 69 (1992) 2411
Ref [4] is Chakravarty, Halperin and Nelson, PRL 60 (1988) 1057; PR B39 (1989) 2344
0
10
20
30
40
T [K
]
0.160 0.055
Metal StrongInsulator Log-T Insulator
La2-xSrxCuO4
Searching for evidence of a quantum critical point in the resistivity
Sharp Insulator-to-Metal Crossover---at optimum doping
Evidence of a Quantum Critical Point ?---at optimum doping---where linear-T resistivity
has been attributed to critical behavior
Y. Ando et al., Physica C341, 1913(2000)
Tc
0.84
0.23 = x0.390.490.510.73
Carrier Concentration
SC
Hall Effect in Bi2Sr2-xLaxCuO6+d
La doping
- Unusual Temperature-dependence of Hall coefficient not understood
?
- What happens below Tc ?
Tc
0.10
Hole Concentration, p
0.18 = p0.160.150.14
0.12
Bi2Sr2-xLaxCuO6+dLa x=0.49Tc =33K
Low Temperature Normal State Hall Effect
Hall Resistivity
0 20 400
50
100
150
1.3K20K25K30K
35K40K50K
ρ ab(µ
Ω c
m)
B(T)
In-plane Resistivity
Bi2Sr2-xLaxCuO6+dLa x=0.49Tc =33K
High-field Hall voltage is linear in field
0 10 20 30 40 50 60
0
0
0
0
0
0
2
4
6
8
10
1.3K
H(T)
5K
20K
30K
40K
ρxy
(µΩ
-cm
)
50K
Y. Ando et al.cond-mat/0004134 (2000)
BSLCO Hall Effect in DC Magnet
0
1
2
3
4
5
6
7
RH(e
/NV c
ell)
Tc
0.84
Carrier Concentration
0.230.390.49
0.510.73
Low-T Hall Effect in BSLCO(two years to develop technique)
37/44
0 20 40 60 80 1000
1
2
3
4
5
6
7
8
RH(e
/NV ce
ll)
T(K)
La=.84 La=.73 La=.51 La=.49 La=.39 La=.23
Calculated Evolution of Hall Coefficient (= 1/Hall density)
upon Doping
Shastry, Shraiman, SinghPRL 70, 2004 (1993)
Measured Evolution of Hall Density upon Doping
We may understand the high-temperaturebehavior of the Hall number from the t-J model…
…but not the peak that develops…
…at temperatures below Tc…and centered on optimum doping
0.10 0.12 0.14 0.16 0.180.0
0.2
0.4
0.6
0.8
1.0
1.2
n H
ALL
, nor
mal
ized
per
Cu
p, hole doping
Peak or Jump near Optimal Doping
Low-TemperatureHall Number
in Bi2Sr2-xLaxCuO6+d
Onset of carriers yields onset of superconducting phase
Hall Number is correlated with Tc
0.10 0.12 0.14 0.16 0.180.0
0.2
0.4
0.6
0.8
1.0
1.2
0
5
10
15
20
25
30
35
40
n H
ALL
, nor
mal
ized
per
Cu
p, hole doping T
c(K)
Critical Temperatureand Hall NumberIn BSLCO
In the underdoped regime…n Hall shows remarkably linear
correlation with Tc
…but not in the overdoped regime…
0.0 0.5 1.00
10
20
30
40c
n HALL
Evidence that the superconducting transition is governed by phase stiffness (superfluid density)
in the underdoped regime
Y. J. Uemura et al., PRL 62, 2317(1989)
0.0 0.5 1.00
10
20
30
40
balakirev_fig3
c
n HALL
TC(K
)
…and so is the Hall number…
Superfluid density in thesuperconducting state corresponds to the Hall density
throughout the underdoped regime
Hall coefficient becomes T-independent at low-T near optimum doping in BSLCO---suggesting a measurement of the Hall number.
Sharp anomaly in doping dependence of the Hall number at optimum doping
---suggesting change in the Fermi Surface
…suggests a Quantum Critical Point governs High-Tc Superconductivity
0.0 0.5 1.00
10
20
30
40
balakirev_fig3
c
n HALL
TC(K
)
Linear relation between Tcand the low-T Hall number
---suggests phase stiffnessgoverns superconducting transitionin the underdoped regime
0 20 40 60 80 1000
1
2
3
4
5 p=0.115
T(K)
p=0.145p=0.14
p=0.13
p=0.12
p=0.15RH(e
/Vce
ll)
To submit a proposal for magnet time, www.magnet.fsu.edu
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