The Experts below are selected from a list of 328827 Experts worldwide ranked by ideXlab platform
Leland Harriger - One of the best experts on this subject based on the ideXlab platform.
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evidence for a spinon fermi surface in a triangular lattice quantum spin liquid candidate
Nature, 2016Co-Authors: Yao Shen, Shoudong Shen, Bingying Pan, Qisi Wang, H C Walker, P Steffens, M Boehm, Yiqing Hao, D L Quinterocastro, Leland HarrigerAbstract:A quantum spin liquid is an exotic quantum State of Matter in which spins are highly entangled and remain disordered down to zero temperature. Such a State of Matter is potentially relevant to high-temperature superconductivity and quantum-information applications, and experimental identification of a quantum spin liquid State is of fundamental importance for our understanding of quantum Matter. Theoretical studies have proposed various quantum-spin-liquid ground States, most of which are characterized by exotic spin excitations with fractional quantum numbers (termed 'spinons'). Here we report neutron scattering measurements of the triangular-lattice antiferromagnet YbMgGaO4 that reveal broad spin excitations covering a wide region of the Brillouin zone. The observed diffusive spin excitation persists at the lowest measured energy and shows a clear upper excitation edge, consistent with the particle-hole excitation of a spinon Fermi surface. Our results therefore point to the existence of a quantum spin liquid State with a spinon Fermi surface in YbMgGaO4, which has a perfect spin-1/2 triangular lattice as in the original proposal of quantum spin liquids.
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spinon fermi surface in a triangular lattice quantum spin liquid ybmggao4
arXiv: Strongly Correlated Electrons, 2016Co-Authors: Yao Shen, Shoudong Shen, Bingying Pan, Qisi Wang, H C Walker, P Steffens, M Boehm, Yiqing Hao, D L Quinterocastro, Leland HarrigerAbstract:Quantum spin liquid (QSL) is an exotic quantum State of Matter in which spins are highly entangled and remain disordered down to zero temperature. In addition to its relevance to high-temperature superconductivity and quantum-information applications, experimental identification of this new State of Matter in its own right is of fundamental importance for our understanding of quantum Matter. Theoretical studies have proposed various QSL ground States, most of which are characterized by exotic spin excitations with fractional quantum numbers (termed `spinon'). However, a conclusive experimental confirmation of any QSL and spinon excitations remains outstanding. Here, we report neutron scattering measurements that reveal broad spin excitations covering a wide region of the Brillouin zone in an extremely clean antiferromagnet YbMgGaO4. The observed diffusive spin excitation persists at the lowest measured energy and shows a clear upper excitation edge, which is naturally accounted by the particle-hole excitation of a spinon Fermi surface. Combining this with the low-temperature heat capacity results we propose that YbMgGaO4 is a gapless U(1) QSL with a spinon Fermi surface. Our results therefore identify a QSL in a perfect spin-1/2 triangular lattice occurring in the original proposal by Anderson.
Shou-cheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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the quantum spin hall effect and topological insulators
arXiv: Materials Science, 2010Co-Authors: Shou-cheng ZhangAbstract:In topological insulators, spin-orbit coupling and time-reversal symmetry combine to form a novel State of Matter predicted to have exotic physical properties.
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fractional charge and quantized current in the quantum spin hall State
arXiv: Mesoscale and Nanoscale Physics, 2007Co-Authors: Taylor L Hughes, Shou-cheng ZhangAbstract:A profound manifestation of topologically non-trivial States of Matter is the occurrence of fractionally charged elementary excitations. The quantum spin Hall insulator State is a fundamentally novel quantum State of Matter that exists at zero external magnetic field. In this work, we show that a magnetic domain wall at the edge of the quantum spin Hall insulator carries one half of the unit of electron charge, and we propose an experiment to directly measure this fractional charge on an individual basis. We also show that as an additional consequence, a rotating magnetic field can induce a quantized dc electric current, and vice versa.
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quantum spin hall effect and topological phase transition in hgte quantum wells
Science, 2006Co-Authors: Taylor L Hughes, Andrei B Bernevig, Shou-cheng ZhangAbstract:We show that the quantum spin Hall (QSH) effect, a State of Matter with topological properties distinct from those of conventional insulators, can be realized in mercury telluride–cadmium telluride semiconductor quantum wells. When the thickness of the quantum well is varied, the electronic State changes from a normal to an “inverted” type at a critical thickness d c . We show that this transition is a topological quantum phase transition between a conventional insulating phase and a phase exhibiting the QSH effect with a single pair of helical edge States. We also discuss methods for experimental detection of the QSH effect.
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Quantum spin hall effect
Physical Review Letters, 2006Co-Authors: B. Andrei Bernevig, Shou-cheng ZhangAbstract:The quantum Hall liquid is a novel State of Matter with profound emergent properties such as fractional charge and statistics. Existence of the quantum Hall effect requires breaking of the time reversal symmetry caused by an external magnetic field. In this work, we predict a quantized spin Hall effect in the absence of any magnetic field, where the intrinsic spin Hall conductance is quantized in units of $2 \frac{e}{4\pi}$. The degenerate quantum Landau levels are created by the spin-orbit coupling in conventional semiconductors in the presence of a strain gradient. This new State of Matter has many profound correlated properties described by a topological field theory.
Yao Shen - One of the best experts on this subject based on the ideXlab platform.
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evidence for a spinon fermi surface in a triangular lattice quantum spin liquid candidate
Nature, 2016Co-Authors: Yao Shen, Shoudong Shen, Bingying Pan, Qisi Wang, H C Walker, P Steffens, M Boehm, Yiqing Hao, D L Quinterocastro, Leland HarrigerAbstract:A quantum spin liquid is an exotic quantum State of Matter in which spins are highly entangled and remain disordered down to zero temperature. Such a State of Matter is potentially relevant to high-temperature superconductivity and quantum-information applications, and experimental identification of a quantum spin liquid State is of fundamental importance for our understanding of quantum Matter. Theoretical studies have proposed various quantum-spin-liquid ground States, most of which are characterized by exotic spin excitations with fractional quantum numbers (termed 'spinons'). Here we report neutron scattering measurements of the triangular-lattice antiferromagnet YbMgGaO4 that reveal broad spin excitations covering a wide region of the Brillouin zone. The observed diffusive spin excitation persists at the lowest measured energy and shows a clear upper excitation edge, consistent with the particle-hole excitation of a spinon Fermi surface. Our results therefore point to the existence of a quantum spin liquid State with a spinon Fermi surface in YbMgGaO4, which has a perfect spin-1/2 triangular lattice as in the original proposal of quantum spin liquids.
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spinon fermi surface in a triangular lattice quantum spin liquid ybmggao4
arXiv: Strongly Correlated Electrons, 2016Co-Authors: Yao Shen, Shoudong Shen, Bingying Pan, Qisi Wang, H C Walker, P Steffens, M Boehm, Yiqing Hao, D L Quinterocastro, Leland HarrigerAbstract:Quantum spin liquid (QSL) is an exotic quantum State of Matter in which spins are highly entangled and remain disordered down to zero temperature. In addition to its relevance to high-temperature superconductivity and quantum-information applications, experimental identification of this new State of Matter in its own right is of fundamental importance for our understanding of quantum Matter. Theoretical studies have proposed various QSL ground States, most of which are characterized by exotic spin excitations with fractional quantum numbers (termed `spinon'). However, a conclusive experimental confirmation of any QSL and spinon excitations remains outstanding. Here, we report neutron scattering measurements that reveal broad spin excitations covering a wide region of the Brillouin zone in an extremely clean antiferromagnet YbMgGaO4. The observed diffusive spin excitation persists at the lowest measured energy and shows a clear upper excitation edge, which is naturally accounted by the particle-hole excitation of a spinon Fermi surface. Combining this with the low-temperature heat capacity results we propose that YbMgGaO4 is a gapless U(1) QSL with a spinon Fermi surface. Our results therefore identify a QSL in a perfect spin-1/2 triangular lattice occurring in the original proposal by Anderson.
M J Tannenbaum - One of the best experts on this subject based on the ideXlab platform.
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recent results in relativistic heavy ion collisions from a new State of Matter to the perfect fluid
Reports on Progress in Physics, 2006Co-Authors: M J TannenbaumAbstract:Experimental physics with relativistic heavy ions dates from 1992 when a beam of 197Au of energy greater than 10 A?GeV/c first became available at the Alternating Gradient Synchrotron at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A?GeV/c at the Super Proton Synchrotron at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac (Gutbrod et al 1989 Rep. Prog. Phys. 52 1267?132) in the late 1970s and early 1980s were at much lower bombarding energies (1A?GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the relativistic heavy ion collider at BNL has produced head-on collisions of two 100 A?GeV beams of fully stripped Au ions, corresponding to nucleon?nucleon centre-of-mass (cm) energy, , total cm energy 200 A?GeV. The objective of this research program is to produce nuclear Matter with extreme density and temperature, possibly resulting in a State of Matter where the quarks and gluons normally confined inside individual nucleons (r < 1?fm) are free to act over distances an order of magnitude larger. Progress from the period 1992 to the present will be reviewed, with reference to previous results from light ion and proton?proton collisions where appropriate. Emphasis will be placed on the measurements which formed the basis for the announcements by the two major laboratories: 'A new State of Matter', by CERN on Febraury 10 2000 and 'The perfect fluid' by BNL on April 19 2005.
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recent results in relativistic heavy ion collisions from a new State of Matter to the perfect fluid
arXiv: Nuclear Experiment, 2006Co-Authors: M J TannenbaumAbstract:Experimental Physics with Relativistic Heavy Ions dates from 1992 when a beam of 197Au of energy greater than 10A GeV/c first became available at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A GeV/c at the Super Proton Synchrotron (SPS) at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac in the late 1970's and early 1980's were at much lower bombarding energies (~ 1 A GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the Relativistic Heavy Ion Collider (RHIC) at BNL has produced head-on collisions of two 100A GeV beams of fully stripped Au ions, corresponding to nucleon-nucleon center-of-mass energy, sqrt(sNN)=200 GeV, total c.m. energy 200A GeV. The objective of this research program is to produce nuclear Matter with extreme density and temperature, possibly resulting in a State of Matter where the quarks and gluons normally confined inside individual nucleons (r < 1 fm) are free to act over distances an order of magnitude larger. Progress from the period 1992 to the present will be reviewed, with reference to previous results from light ion and proton-proton collisions where appropriate. Emphasis will be placed on the measurements which formed the basis for the announcements by the two major laboratories: "A new State of Matter", by CERN on Feb 10, 2000 and "The perfect fluid", by BNL on April 19, 2005.
P Steffens - One of the best experts on this subject based on the ideXlab platform.
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evidence for a spinon fermi surface in a triangular lattice quantum spin liquid candidate
Nature, 2016Co-Authors: Yao Shen, Shoudong Shen, Bingying Pan, Qisi Wang, H C Walker, P Steffens, M Boehm, Yiqing Hao, D L Quinterocastro, Leland HarrigerAbstract:A quantum spin liquid is an exotic quantum State of Matter in which spins are highly entangled and remain disordered down to zero temperature. Such a State of Matter is potentially relevant to high-temperature superconductivity and quantum-information applications, and experimental identification of a quantum spin liquid State is of fundamental importance for our understanding of quantum Matter. Theoretical studies have proposed various quantum-spin-liquid ground States, most of which are characterized by exotic spin excitations with fractional quantum numbers (termed 'spinons'). Here we report neutron scattering measurements of the triangular-lattice antiferromagnet YbMgGaO4 that reveal broad spin excitations covering a wide region of the Brillouin zone. The observed diffusive spin excitation persists at the lowest measured energy and shows a clear upper excitation edge, consistent with the particle-hole excitation of a spinon Fermi surface. Our results therefore point to the existence of a quantum spin liquid State with a spinon Fermi surface in YbMgGaO4, which has a perfect spin-1/2 triangular lattice as in the original proposal of quantum spin liquids.
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spinon fermi surface in a triangular lattice quantum spin liquid ybmggao4
arXiv: Strongly Correlated Electrons, 2016Co-Authors: Yao Shen, Shoudong Shen, Bingying Pan, Qisi Wang, H C Walker, P Steffens, M Boehm, Yiqing Hao, D L Quinterocastro, Leland HarrigerAbstract:Quantum spin liquid (QSL) is an exotic quantum State of Matter in which spins are highly entangled and remain disordered down to zero temperature. In addition to its relevance to high-temperature superconductivity and quantum-information applications, experimental identification of this new State of Matter in its own right is of fundamental importance for our understanding of quantum Matter. Theoretical studies have proposed various QSL ground States, most of which are characterized by exotic spin excitations with fractional quantum numbers (termed `spinon'). However, a conclusive experimental confirmation of any QSL and spinon excitations remains outstanding. Here, we report neutron scattering measurements that reveal broad spin excitations covering a wide region of the Brillouin zone in an extremely clean antiferromagnet YbMgGaO4. The observed diffusive spin excitation persists at the lowest measured energy and shows a clear upper excitation edge, which is naturally accounted by the particle-hole excitation of a spinon Fermi surface. Combining this with the low-temperature heat capacity results we propose that YbMgGaO4 is a gapless U(1) QSL with a spinon Fermi surface. Our results therefore identify a QSL in a perfect spin-1/2 triangular lattice occurring in the original proposal by Anderson.
