The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Natalia B Perkins - One of the best experts on this subject based on the ideXlab platform.
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Vacancy-Induced Low-Energy Density of States in the Kitaev Spin Liquid
Physical Review X, 2021Co-Authors: Wen-han Kao, Johannes Knolle, Roderich Moessner, Gábor B. Halász, Natalia B PerkinsAbstract:A small concentration of vacancies in the Kitaev model of quantum spin liquids (QSLs) alter its Low-Energy physics, offering a plausible explanation for recent experimental results on the QSL-hosting compound H${}_{3}$LiIr${}_{2}$O${}_{6}$.
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Vacancy-induced Low-Energy Density of states in the Kitaev spin liquid
arXiv: Strongly Correlated Electrons, 2020Co-Authors: Wen-han Kao, Johannes Knolle, Roderich Moessner, Gábor B. Halász, Natalia B PerkinsAbstract:The Kitaev honeycomb model has attracted significant attention due to its exactly solvable spin-liquid ground state with fractionalized Majorana excitations and its possible materialization in magnetic Mott insulators with strong spin-orbit couplings. Recently, the 5d-electron compound H$_{3}$LiIr$_{2}$O$_{6}$ has shown to be a strong candidate for Kitaev physics considering the absence of any signs of a long-range ordered magnetic state. In this work, we demonstrate that a finite Density of random vacancies in the Kitaev model gives rise to a striking pileup of Low-Energy Majorana eigenmodes and reproduces the apparent power-law upturn in the specific heat measurements of H$_{3}$LiIr$_{2}$O$_{6}$. Physically, the vacancies can originate from various sources such as missing magnetic moments or the presence of non-magnetic impurities (true vacancies), or from local weak couplings of magnetic moments due to strong but rare bond randomness (quasivacancies). We show numerically that the vacancy effect is readily detectable even at Low vacancy concentrations and that it is not very sensitive neither to nature of vacancies nor to different flux backgrounds. We also study the response of the site-diluted Kitaev spin liquid to the three-spin interaction term, which breaks time-reversal symmetry and imitates an external magnetic field. We propose a field-induced flux-sector transition where the ground state becomes flux free for larger fields, resulting in a clear suppression of the Low temperature specific heat. Finally, we discuss the effect of dangling Majorana fermions in the case of true vacancies and show that their coupling to an applied magnetic field via the Zeeman interaction can also account for the scaling behavior in the high-field limit observed in H$_{3}$LiIr$_{2}$O$_{6}$.
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bond disordered spin liquid and the honeycomb iridate h3liir2o6 abundant Low Energy Density of states from random majorana hopping
Physical Review Letters, 2019Co-Authors: Johannes Knolle, Roderich Moessner, Natalia B PerkinsAbstract:: The 5d-electron honeycomb compound H_{3}LiIr_{2}O_{6} [K. Kitagawa et al., Nature (London) 554, 341 (2018)NATUAS0028-083610.1038/nature25482] exhibits an apparent quantum spin liquid state. In this intercalated spin-orbital compound, a remarkable pileup of Low-Energy states was experimentally observed in specific heat and spin relaxation. We show that a bond-disordered Kitaev model can naturally account for this phenomenon, suggesting that disorder plays an essential role in its theoretical description. In the exactly soluble Kitaev model, we obtain, via spin fractionalization, a random bipartite hopping problem of Majorana fermions in a random flux background. This has a divergent Low-Energy Density of states of the required power-law form N(E)∝E^{-ν} with a drifting exponent which takes on the value ν≈1/2 for relatively strong bond disorder. Breaking time-reversal symmetry removes the divergence of the Density of states, as does applying a magnetic field in experiment. We discuss the implication of our scenario, both for future experiments and from a broader perspective.
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Bond-Disordered Spin Liquid and the Honeycomb Iridate H 3 LiIr 2 O 6 : Abundant Low-Energy Density of States from Random Majorana Hopping
Physical review letters, 2019Co-Authors: Johannes Knolle, Roderich Moessner, Natalia B PerkinsAbstract:The $5d$-electron honeycomb compound ${\mathrm{H}}_{3}{\mathrm{LiIr}}_{2}{\mathrm{O}}_{6}$ [K. Kitagawa et al., Nature (London) 554, 341 (2018)] exhibits an apparent quantum spin liquid state. In this intercalated spin-orbital compound, a remarkable pileup of Low-Energy states was experimentally observed in specific heat and spin relaxation. We show that a bond-disordered Kitaev model can naturally account for this phenomenon, suggesting that disorder plays an essential role in its theoretical description. In the exactly soluble Kitaev model, we obtain, via spin fractionalization, a random bipartite hopping problem of Majorana fermions in a random flux background. This has a divergent Low-Energy Density of states of the required power-law form $N(E)\ensuremath{\propto}{E}^{\ensuremath{-}\ensuremath{\nu}}$ with a drifting exponent which takes on the value $\ensuremath{\nu}\ensuremath{\approx}1/2$ for relatively strong bond disorder. Breaking time-reversal symmetry removes the divergence of the Density of states, as does applying a magnetic field in experiment. We discuss the implication of our scenario, both for future experiments and from a broader perspective.
Jamy D Ard - One of the best experts on this subject based on the ideXlab platform.
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Physical Activity Patterns During Weight Maintenance FolLowing a Low-Energy Density Dietary Intervention
Obesity (Silver Spring Md.), 2007Co-Authors: Tiffany L. Cox, Christie Z Malpede, Douglas C Heimburger, C. Suzanne Henson, Renee A. Desmond, Lori E. Faulk, Rory A. Myer, Jamy D ArdAbstract:Objective: The objective was to determine the role of physical activity (PA) and Energy intake on weight maintenance among former University of Alabama at Birmingham EatRight Weight Management Program participants. Research Methods and Procedures: Eighty-nine former participants completed folLow-up visits ≥1 year after completing EatRight. BMI was calculated using measured height and weight. Diet intake was estimated from 4-day food records. PA was assessed using a module from the Behavioral Risk Factor Surveillance System Survey. Cut-off points were chosen based on the distribution of minutes of activity. For moderate and total activity, cut-off points were 0, 1 to 30, 31 to 60, and >60 minutes. For vigorous activity, the categories were 0, 1 to 20, 21 to 30, and >30 minutes. General linear models determined the association of PA with change in weight at folLow-up controlling for gender and total Energy intake (kcal/d). Results: At folLow-up, 80% (n = 71) of participants maintained (regained
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weight maintenance 2 years after participation in a weight loss program promoting Low Energy Density foods
Obesity, 2006Co-Authors: Lori F Greene, Christie Z Malpede, Suzanne C Henson, Kathy Hubbert, Douglas C Heimburger, Jamy D ArdAbstract:Objective: Observational study designed to determine weight outcomes and associated dietary intake patterns for a sample of participants ≥1 year after completing the University of Alabama at Birmingham EatRight Weight Management Program. Research Methods and Procedures: Seventy-four former participants (64% women) completed folLow-up visits ≥1 year after participating in EatRight, which promotes Low-Energy Density, high-complex carbohydrate foods. Weight maintenance was defined as gaining <5% of body weight since completion of the EatRight program and staying beLow their program entry weight. Those who gained ≥5% of their body weight since completion were classified as gainers. Results: During EatRight, participants of the folLow-up study lost an average of 4.0 kg. After a mean folLow-up time of 2.2 years, the average weight change was +0.59 kg (mean BMI, 32.5 kg/m2). Seventy-eight percent of participants gained <5% of their body weight; 46% had no weight regain or continued weight loss. Unadjusted mean intake for maintainers was 1608 kcal, whereas calorie intake for gainers was 1989 kcal. Despite eating slightly fewer calories (adjusted difference, 244; p = 0.058), maintainers ate a similar amount of food, resulting in a Lower Energy-Density pattern (p = 0.016) compared with those who regained ≥5% of body weight. Gainers also reported consuming larger portions of several food groups. Discussion: Our results indicate that Low-Energy-Density eating habits are associated with long-term weight maintenance. Those who maintain weight after the EatRight program consume a Low-Energy-Density dietary pattern and smaller portions of food groups potentially high in Energy Density than those who regain weight.
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Weight maintenance 2 years after participation in a weight loss program promoting Low-Energy Density foods.
Obesity (Silver Spring Md.), 2006Co-Authors: Lori F Greene, Christie Z Malpede, Kathy Hubbert, Douglas C Heimburger, C. Suzanne Henson, Jamy D ArdAbstract:Objective: Observational study designed to determine weight outcomes and associated dietary intake patterns for a sample of participants ≥1 year after completing the University of Alabama at Birmingham EatRight Weight Management Program. Research Methods and Procedures: Seventy-four former participants (64% women) completed folLow-up visits ≥1 year after participating in EatRight, which promotes Low-Energy Density, high-complex carbohydrate foods. Weight maintenance was defined as gaining
Johannes Knolle - One of the best experts on this subject based on the ideXlab platform.
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Vacancy-Induced Low-Energy Density of States in the Kitaev Spin Liquid
Physical Review X, 2021Co-Authors: Wen-han Kao, Johannes Knolle, Roderich Moessner, Gábor B. Halász, Natalia B PerkinsAbstract:A small concentration of vacancies in the Kitaev model of quantum spin liquids (QSLs) alter its Low-Energy physics, offering a plausible explanation for recent experimental results on the QSL-hosting compound H${}_{3}$LiIr${}_{2}$O${}_{6}$.
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Vacancy-induced Low-Energy Density of states in the Kitaev spin liquid
arXiv: Strongly Correlated Electrons, 2020Co-Authors: Wen-han Kao, Johannes Knolle, Roderich Moessner, Gábor B. Halász, Natalia B PerkinsAbstract:The Kitaev honeycomb model has attracted significant attention due to its exactly solvable spin-liquid ground state with fractionalized Majorana excitations and its possible materialization in magnetic Mott insulators with strong spin-orbit couplings. Recently, the 5d-electron compound H$_{3}$LiIr$_{2}$O$_{6}$ has shown to be a strong candidate for Kitaev physics considering the absence of any signs of a long-range ordered magnetic state. In this work, we demonstrate that a finite Density of random vacancies in the Kitaev model gives rise to a striking pileup of Low-Energy Majorana eigenmodes and reproduces the apparent power-law upturn in the specific heat measurements of H$_{3}$LiIr$_{2}$O$_{6}$. Physically, the vacancies can originate from various sources such as missing magnetic moments or the presence of non-magnetic impurities (true vacancies), or from local weak couplings of magnetic moments due to strong but rare bond randomness (quasivacancies). We show numerically that the vacancy effect is readily detectable even at Low vacancy concentrations and that it is not very sensitive neither to nature of vacancies nor to different flux backgrounds. We also study the response of the site-diluted Kitaev spin liquid to the three-spin interaction term, which breaks time-reversal symmetry and imitates an external magnetic field. We propose a field-induced flux-sector transition where the ground state becomes flux free for larger fields, resulting in a clear suppression of the Low temperature specific heat. Finally, we discuss the effect of dangling Majorana fermions in the case of true vacancies and show that their coupling to an applied magnetic field via the Zeeman interaction can also account for the scaling behavior in the high-field limit observed in H$_{3}$LiIr$_{2}$O$_{6}$.
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bond disordered spin liquid and the honeycomb iridate h3liir2o6 abundant Low Energy Density of states from random majorana hopping
Physical Review Letters, 2019Co-Authors: Johannes Knolle, Roderich Moessner, Natalia B PerkinsAbstract:: The 5d-electron honeycomb compound H_{3}LiIr_{2}O_{6} [K. Kitagawa et al., Nature (London) 554, 341 (2018)NATUAS0028-083610.1038/nature25482] exhibits an apparent quantum spin liquid state. In this intercalated spin-orbital compound, a remarkable pileup of Low-Energy states was experimentally observed in specific heat and spin relaxation. We show that a bond-disordered Kitaev model can naturally account for this phenomenon, suggesting that disorder plays an essential role in its theoretical description. In the exactly soluble Kitaev model, we obtain, via spin fractionalization, a random bipartite hopping problem of Majorana fermions in a random flux background. This has a divergent Low-Energy Density of states of the required power-law form N(E)∝E^{-ν} with a drifting exponent which takes on the value ν≈1/2 for relatively strong bond disorder. Breaking time-reversal symmetry removes the divergence of the Density of states, as does applying a magnetic field in experiment. We discuss the implication of our scenario, both for future experiments and from a broader perspective.
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Bond-Disordered Spin Liquid and the Honeycomb Iridate H 3 LiIr 2 O 6 : Abundant Low-Energy Density of States from Random Majorana Hopping
Physical review letters, 2019Co-Authors: Johannes Knolle, Roderich Moessner, Natalia B PerkinsAbstract:The $5d$-electron honeycomb compound ${\mathrm{H}}_{3}{\mathrm{LiIr}}_{2}{\mathrm{O}}_{6}$ [K. Kitagawa et al., Nature (London) 554, 341 (2018)] exhibits an apparent quantum spin liquid state. In this intercalated spin-orbital compound, a remarkable pileup of Low-Energy states was experimentally observed in specific heat and spin relaxation. We show that a bond-disordered Kitaev model can naturally account for this phenomenon, suggesting that disorder plays an essential role in its theoretical description. In the exactly soluble Kitaev model, we obtain, via spin fractionalization, a random bipartite hopping problem of Majorana fermions in a random flux background. This has a divergent Low-Energy Density of states of the required power-law form $N(E)\ensuremath{\propto}{E}^{\ensuremath{-}\ensuremath{\nu}}$ with a drifting exponent which takes on the value $\ensuremath{\nu}\ensuremath{\approx}1/2$ for relatively strong bond disorder. Breaking time-reversal symmetry removes the divergence of the Density of states, as does applying a magnetic field in experiment. We discuss the implication of our scenario, both for future experiments and from a broader perspective.
Roderich Moessner - One of the best experts on this subject based on the ideXlab platform.
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Vacancy-Induced Low-Energy Density of States in the Kitaev Spin Liquid
Physical Review X, 2021Co-Authors: Wen-han Kao, Johannes Knolle, Roderich Moessner, Gábor B. Halász, Natalia B PerkinsAbstract:A small concentration of vacancies in the Kitaev model of quantum spin liquids (QSLs) alter its Low-Energy physics, offering a plausible explanation for recent experimental results on the QSL-hosting compound H${}_{3}$LiIr${}_{2}$O${}_{6}$.
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Vacancy-induced Low-Energy Density of states in the Kitaev spin liquid
arXiv: Strongly Correlated Electrons, 2020Co-Authors: Wen-han Kao, Johannes Knolle, Roderich Moessner, Gábor B. Halász, Natalia B PerkinsAbstract:The Kitaev honeycomb model has attracted significant attention due to its exactly solvable spin-liquid ground state with fractionalized Majorana excitations and its possible materialization in magnetic Mott insulators with strong spin-orbit couplings. Recently, the 5d-electron compound H$_{3}$LiIr$_{2}$O$_{6}$ has shown to be a strong candidate for Kitaev physics considering the absence of any signs of a long-range ordered magnetic state. In this work, we demonstrate that a finite Density of random vacancies in the Kitaev model gives rise to a striking pileup of Low-Energy Majorana eigenmodes and reproduces the apparent power-law upturn in the specific heat measurements of H$_{3}$LiIr$_{2}$O$_{6}$. Physically, the vacancies can originate from various sources such as missing magnetic moments or the presence of non-magnetic impurities (true vacancies), or from local weak couplings of magnetic moments due to strong but rare bond randomness (quasivacancies). We show numerically that the vacancy effect is readily detectable even at Low vacancy concentrations and that it is not very sensitive neither to nature of vacancies nor to different flux backgrounds. We also study the response of the site-diluted Kitaev spin liquid to the three-spin interaction term, which breaks time-reversal symmetry and imitates an external magnetic field. We propose a field-induced flux-sector transition where the ground state becomes flux free for larger fields, resulting in a clear suppression of the Low temperature specific heat. Finally, we discuss the effect of dangling Majorana fermions in the case of true vacancies and show that their coupling to an applied magnetic field via the Zeeman interaction can also account for the scaling behavior in the high-field limit observed in H$_{3}$LiIr$_{2}$O$_{6}$.
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bond disordered spin liquid and the honeycomb iridate h3liir2o6 abundant Low Energy Density of states from random majorana hopping
Physical Review Letters, 2019Co-Authors: Johannes Knolle, Roderich Moessner, Natalia B PerkinsAbstract:: The 5d-electron honeycomb compound H_{3}LiIr_{2}O_{6} [K. Kitagawa et al., Nature (London) 554, 341 (2018)NATUAS0028-083610.1038/nature25482] exhibits an apparent quantum spin liquid state. In this intercalated spin-orbital compound, a remarkable pileup of Low-Energy states was experimentally observed in specific heat and spin relaxation. We show that a bond-disordered Kitaev model can naturally account for this phenomenon, suggesting that disorder plays an essential role in its theoretical description. In the exactly soluble Kitaev model, we obtain, via spin fractionalization, a random bipartite hopping problem of Majorana fermions in a random flux background. This has a divergent Low-Energy Density of states of the required power-law form N(E)∝E^{-ν} with a drifting exponent which takes on the value ν≈1/2 for relatively strong bond disorder. Breaking time-reversal symmetry removes the divergence of the Density of states, as does applying a magnetic field in experiment. We discuss the implication of our scenario, both for future experiments and from a broader perspective.
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Bond-Disordered Spin Liquid and the Honeycomb Iridate H 3 LiIr 2 O 6 : Abundant Low-Energy Density of States from Random Majorana Hopping
Physical review letters, 2019Co-Authors: Johannes Knolle, Roderich Moessner, Natalia B PerkinsAbstract:The $5d$-electron honeycomb compound ${\mathrm{H}}_{3}{\mathrm{LiIr}}_{2}{\mathrm{O}}_{6}$ [K. Kitagawa et al., Nature (London) 554, 341 (2018)] exhibits an apparent quantum spin liquid state. In this intercalated spin-orbital compound, a remarkable pileup of Low-Energy states was experimentally observed in specific heat and spin relaxation. We show that a bond-disordered Kitaev model can naturally account for this phenomenon, suggesting that disorder plays an essential role in its theoretical description. In the exactly soluble Kitaev model, we obtain, via spin fractionalization, a random bipartite hopping problem of Majorana fermions in a random flux background. This has a divergent Low-Energy Density of states of the required power-law form $N(E)\ensuremath{\propto}{E}^{\ensuremath{-}\ensuremath{\nu}}$ with a drifting exponent which takes on the value $\ensuremath{\nu}\ensuremath{\approx}1/2$ for relatively strong bond disorder. Breaking time-reversal symmetry removes the divergence of the Density of states, as does applying a magnetic field in experiment. We discuss the implication of our scenario, both for future experiments and from a broader perspective.
Allan Geliebter - One of the best experts on this subject based on the ideXlab platform.
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supermarket discounts of Low Energy Density foods effects on purchasing food intake and body weight
Obesity, 2013Co-Authors: Tatiana Ungredda, Christopher N. Ochner, Rachel Miller, Allan Geliebter, Maria Bernaleskorins, Dominica Hernandez, Laura KolbeAbstract:Objective To assess the effects of a 50% discount on Low-Energy Density (ED) fruits and vegetables (F&V), bottled water, and diet sodas on shoppers' purchasing, food intake, and body weight. Design and Methods A randomized, controlled trial was conducted at two Manhattan supermarkets, in which a 4-week baseline period (no discounts) preceded an 8-week intervention period (50% discount), and a 4-week folLow-up period (no discounts). Twenty-four hour dietary recall, as well as body weight and body composition measures were obtained every 4 weeks. Participants (n = 47, 33f; 14m) were overweight and obese (BMI ≥ 25) shoppers. Results Purchasing of F&V during intervention was greater in the discount group than in the control group (P < 0.0001). Purchasing of these items by the discount group relative to the control group during folLow-up was reduced from intervention (P = 0.002), but still remained higher than during baseline (P = 0.01), indicating a partially sustained effect. Intake of F&V increased from baseline to intervention in the discount group relative to the control group (P = 0.037) and was sustained during folLow-up. Body weight change did not differ significantly between groups, although post hoc analysis indicated a change within the discount group (−1.1 kg, P = 0.006) but not within the control group. Conclusions Discounts of Low-ED F&V led to increased purchasing and intake of those foods.
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Supermarket Discounts of Low-Energy Density Foods: Effects on Purchasing, Food Intake, and Body Weight
Obesity, 2013Co-Authors: Allan Geliebter, Ian Yi Han Ang, Maria Bernales-korins, Dominica B. Hernandez, Tatiana Ungredda, Christopher N. Ochner, Rachel Miller, Laura KolbeAbstract:Objective To assess the effects of a 50% discount on Low-Energy Density (ED) fruits and vegetables (F&V), bottled water, and diet sodas on shoppers' purchasing, food intake, and body weight. Design and Methods A randomized, controlled trial was conducted at two Manhattan supermarkets, in which a 4-week baseline period (no discounts) preceded an 8-week intervention period (50% discount), and a 4-week folLow-up period (no discounts). Twenty-four hour dietary recall, as well as body weight and body composition measures were obtained every 4 weeks. Participants (n = 47, 33f; 14m) were overweight and obese (BMI ≥ 25) shoppers. Results Purchasing of F&V during intervention was greater in the discount group than in the control group (P
