Transport properties of a spin-1/2 Heisenberg chain with an embedded spin-S impurity

The finite temperature transport properties of a spin-1/2 anisotropic Heisenberg chain with an embedded spin-S impurity are studied. Using primarily numerical diagonalization techniques, we study the dependence of the dynamical spin and thermal conductivities on the lattice size, the magnitude of the impurity spin, the host-impurity coupling, the easy axis anisotropy, as well as the dependence on temperature. Particularly for the temperature dependence, we discuss the screening of the impurity by the chain eventually leading to the cutting or healing of the host chain. Numerical results are supported by analytical arguments obtained in the strong host-impurity coupling regime.Comment: 7 pages, 10 figure

Thermal transport in a spin-1/2 Heisenberg chain coupled to a (non) magnetic impurity

We explore the effect of a (non) magnetic impurity on the thermal transport of the spin-1/2 Heisenberg chain model. This unique system allows to probe Kondo-type phenomena in a prototype strongly correlated system. Using numerical diagonalization techniques we study the scaling of the frequency dependent thermal conductivity with system size and host-impurity coupling strength as well as the dependence on temperature. We focus in particular on the analysis of cutting-healing of weak links or a magnetic impurity by the host chain via Kondo-like screening as the temperature is lowered.Comment: 7 pages, 12 figure

Simulation of Quantum Magnetism in Mixed Spin Systems with Impurity Doped Ion Crystal

We propose the realization of linear crystals of cold ions which contain different atomic species for investigating quantum phase transitions and frustration effects in spin system beyond the commonly discussed case of $s=1/2$. Mutual spin-spin interactions between ions can be tailored via the Zeeman effect by applying oscillating magnetic fields with strong gradients. Further, collective vibrational modes in the mixed ion crystal can be used to enhance and to vary the strength of spin-spin interactions and even to switch those forces from a ferro- to an antiferromagnetic character. We consider the behavior of the effective spin-spin couplings in an ion crystal of spin-1/2 ions doped with high magnetic moment ions with spin S=3. We analyze the ground state phase diagram and find regions with different spin orders including ferrimagnetic states. In the most simple non-trivial example we deal with a linear $\{$Ca$^+$, Mn$^+$, Ca$^+\}$ crystal with spins of \{1/2,3,1/2}. To show the feasibility with current state-of-the-art experiments, we discuss how quantum phases might be detected using a collective Stern-Gerlach effect of the ion crystal and high resolution spectroscopy. Here, the state-dependent laser-induced fluorescence of the indicator spin-1/2 ion, of species $^{40}$Ca$^+$, reveals also the spin state of the simulator spin-3 ions, $^{50}$Mn$^+$ as this does not possess suitable levels for optical excitation and detection.Comment: 15 pages, 5 figure

Atacamite Cu2Cl(OH)3: A model compound for the S = 1/2 sawtooth chain?

We present a combined experimental and theoretical study of the mineral atacamite Cu2Cl(OH)3.Based on ab initio band structure calculations, we derive a magnetic coupling scheme of essentially a S = 1/2 sawtooth chain. Experimentally, we fully characterize the long-range antiferromagnetically ordered state and field-induced behavior, here for H k b axis. Magnetic order is suppressed by magnetic fields of ∼ 20 T, while beginning at 31.5 T we observe a wide magnetization plateau at half of the saturation magnetization, Msat/2. Numerical calculations for the magnetization M(H) of the quantum sawtooth chain reveal a plateau at Msat/2, raising the issue of the understandingof its microscopic nature.Fil: Heinze, L.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Jeschke, H.. Okayama University; Japón. Goethe Universitat Frankfurt; AlemaniaFil: Metavitsiadis, A.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Reehuis, M.. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; AlemaniaFil: Feyerherm, R.. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; AlemaniaFil: Hoffmann, J. U.. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; AlemaniaFil: Wolter, A. U. B.. Leibniz Institute For Solid State And Materials Researc; AlemaniaFil: Ding, X.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Zapf, V.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Corvalán Moya, Carolina del Huerto. Comisión Nacional de Energía Atómica; Argentina. Los Alamos National High Magnetic Field Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Weickert, F.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Jaime, M.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Rule, K. C.. Australian Nuclear Science And Technology Organisation; AustraliaFil: Menzel, D.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Valenti, R.. Goethe Universitat Frankfurt; AlemaniaFil: Brenig, W.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Süllow, S.. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; Alemani

Magnetization Process of Atacamite: A Case of Weakly Coupled S=1 /2 Sawtooth Chains

We present a combined experimental and theoretical study of the mineral atacamite Cu2Cl(OH)3. Density-functional theory yields a Hamiltonian describing anisotropic sawtooth chains with weak 3D connections. Experimentally, we fully characterize the antiferromagnetically ordered state. Magnetic order shows a complex evolution with the magnetic field, while, starting at 31.5 T, we observe a plateaulike magnetization at about Msat/2. Based on complementary theoretical approaches, we show that the latter is unrelated to the known magnetization plateau of a sawtooth chain. Instead, we provide evidence that the magnetization process in atacamite is a field-driven canting of a 3D network of weakly coupled sawtooth chains that form giant moments.Fil: Heinze, L.. Technische Universität Braunschweig; AlemaniaFil: Jeschke, H. O.. Okayama University; JapónFil: Mazin, I. I.. George Mason University; Estados UnidosFil: Metavitsiadis, A.. Technische Universität Braunschweig; AlemaniaFil: Reehuis, M.. Helmholtz-zentrum Berlin Für Materialien Und Energie; AlemaniaFil: Feyerherm, R.. Helmholtz-zentrum Berlin Für Materialien Und Energie; AlemaniaFil: Hoffmann, J. U.. Helmholtz-zentrum Berlin Für Materialien Und Energie; AlemaniaFil: Bartkowiak, M.. Helmholtz-zentrum Berlin Für Materialien Und Energie; AlemaniaFil: Prokhnenko, O.. Helmholtz-zentrum Berlin Für Materialien Und Energie; AlemaniaFil: Wolter, A. U. B.. Institute for Solid State and Materials Research; AlemaniaFil: Ding, X.. National High Magnetic Field Laboratory Los Almos; Estados UnidosFil: Zapf, V. S.. National High Magnetic Field Laboratory Los Almos; Estados UnidosFil: Corvalán Moya, Carolina del Huerto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. National High Magnetic Field Laboratory Los Almos; Estados Unidos. Comisión Nacional de Energía Atómica; ArgentinaFil: Weickert, F.. National High Magnetic Field Laboratory Los Almos; Estados UnidosFil: Jaime, M.. National High Magnetic Field Laboratory Los Almos; Estados UnidosFil: Rule, K. C.. Australian Nuclear Science And Technology Organisation; AustraliaFil: Menzel, D.. Technische Universität Braunschweig; AlemaniaFil: Valentí, R.. Goethe Universitat Frankfurt; AlemaniaFil: Brenig, W.. Technische Universität Braunschweig; AlemaniaFil: Süllow, S.. Technische Universität Braunschweig; Alemani

Magnetization Process of Atacamite A Case of Weakly Coupled S 1 2 Sawtooth Chains

We present a combined experimental and theoretical study of the mineral atacamite Cu2Cl OH 3. Density functional theory yields a Hamiltonian describing anisotropic sawtooth chains with weak 3D connections. Experimentally, we fully characterize the antiferromagnetically ordered state. Magnetic order shows a complex evolution with the magnetic field, while, starting at 31.5 T, we observe a plateaulike magnetization at about Msat 2. Based on complementary theoretical approaches, we show that the latter is unrelated to the known magnetization plateau of a sawtooth chain. Instead, we provide evidence that the magnetization process in atacamite is a field driven canting of a 3D network of weakly coupled sawtooth chains that form giant moment