Bulletin of the American Physical Society
APS March Meeting 2023
Volume 68, Number 3
Las Vegas, Nevada (March 5-10)
Virtual (March 20-22); Time Zone: Pacific Time
Session T29: Strongly Correlated Systems, Including Quantum Fluids and Solids XVII |
Hide Abstracts |
Sponsoring Units: DCMP Chair: Michael Hertaeg, Durham University Room: Room 221 |
Thursday, March 9, 2023 11:30AM - 11:42AM |
T29.00001: Density Matrix Renormalization Group (DMRG) on Two-Dimensional Quantum Spin Liquids In A Kagome Lattice Chad E Germany, Bryan K Clark Materials like pyrochlore and herbertsmithite have shown promising evidence of spin liquid behavior in neutron scattering experiments motivating the study of quantum spin liquids on the two dimensional kagome lattice. There are multiple different spin-liquids on the kagome lattice that can be constructed from different Hamiltonians. The question remains of whether these spin liquids are all connected via the same phase or is there a phase transition no matter what the path. Answering this question will allow us to contribute to the identity of the S= 1/2 kagome Heisenberg antiferromagnet spin liquid as well as discovering Hamiltonians that support spin liquids. Using DMRG and the calculation of useful observables we mapped out a phase diagram of different spin liquids. |
Thursday, March 9, 2023 11:42AM - 11:54AM |
T29.00002: Phase Transitions in Quasi-One-Dimensional (TaSe4)2I Weyl Semimetal Nanoribbons Revealed with Electronic Noise Spectroscopy Subhajit Ghosh, Alexander A Balandin, Fariborz Kargar, Tina T Salguero, Sergey Rumyantsev, Nicholas Sesing, Zahra Barani, Dong Yan We investigated low-frequency current fluctuations, also referred to as excess noise, in quasi-one-dimensional (TaSe4)2I Weyl semimetal nanoribbons. It was found that the noise spectral density is of the 1/f type and scales with the square of the current (f is the frequency). The noise spectral density increases by almost an order of magnitude and develops Lorentzian features near the temperature T~225 K. These spectral changes were attributed to the charge-density-wave phase transition. The noise level, normalized by the channel area, in these Weyl semimetal nanoribbons was surprisingly low when measured below and above the Peierls transition temperature. We studied the noise scaling with the cross-sectional area of the Weyl semimetal nanoribbons. The nature of the phase transition that shows non-metallic behavior below and above the transition point will be discussed. Obtained results shed light on the specifics of electron transport in quasi-1D topological Weyl semimetals and can be useful for their proposed applications as downscaled interconnects. |
Thursday, March 9, 2023 11:54AM - 12:06PM |
T29.00003: Non-interacting universality of quasiperiodic-induced localization transitions in 1d Miguel d Gonçalves, Bruno Amorim, Eduardo V Castro, Pedro Ribeiro, Jedediah H Pixley We devise a renormalization-group method to analyze the localization properties of interacting and non-interacting [1,2] many-body ground-states in 1d quasiperiodic systems. |
Thursday, March 9, 2023 12:06PM - 12:18PM |
T29.00004: Poor Man's Approach to Exploring the Electronic Structures in Transition-Metal Oxides Yong Zhong, Kyuho Lee, Tiffany Chun-An Wang, Donghui Lu, Makoto Hashimoto, Harold Hwang, Zhixun Shen In transition metal oxides (TMOs), the interactions among electronic spins, charges and orbitals account for the exotic properties such as metal-insulator transition, high-temperature superconductivity and colossal magnetoresistance. However, decent angle-resolved photoemission spectroscopy (ARPES) data are still lacking in many "uncleavable" perovskite-structure TMOs, which hinders the comprehensive understanding of the emergent phenomena in these correlated materials. Here, we develop a new method to prepare clean surfaces of Nd0.8Sr0.2NiO3 and La0.7Ca0.3MnO3 thin films, and investigate their electronic structures to track the microscopic origin of the metal-insulator transitions in these two systems. Our method can be generalized to study the 4d and 5d TMOs. |
Thursday, March 9, 2023 12:18PM - 12:30PM |
T29.00005: Ferromagnetic quantum critical point in a Ni1-xRhx alloy with x = 0.375 Chien-Lung Huang, Rong-Zhu Lin A chemical substitution-induced ferromagnetic quantum critical point in polycrystalline Ni1−xRhx alloys. Non-Fermi liquid behavior is observed close to the critical concentration xcrit = 0.375, where the Curie temperature vanishes. The electronic specific heat Cel/T, the volume thermal expansion coefficient αV/T, and the Grüneisen ratio Γ ≡ αV/Cel diverge logarithmically upon cooling to absolute zero, providing strong evidence of a ferromagnetic quantum critical point in Ni1−xRhx [1]. We further perform a hyperscaling analysis of the thermodynamic measurements as a function of temperature and magnetic field for Ni1−xRhx with xcrit = 0.375. The obtained critical exponents agree well with the theory proposed by Belitz, Kirkpatrick, and Vojta for a disorder tuned quantum critical point in the preasymptotic region [2]. |
Thursday, March 9, 2023 12:30PM - 12:42PM |
T29.00006: Bootstrapping the O(3) Model from Dimensions 2 to 3 Robert A Jones, Max Metlitski We present the results of a numerical conformal bootstrap study of the O(3) model in dimensions between 2 and 3. In 3 dimensions, the O(3) model comes in two flavors according to whether or not hedgehog topological defects are allowed or suppressed. The hedgehog-suppressed model is of interest as the prototypical deconfined quantum critical point. While the O(N) fixed point in 3 dimensions is strongly coupled and thus not immediately amenable to study, one can gain perturbative control of the problem by working in 2+epsilon dimensions. One can thus ask whether this 2+epsilon expansion breaks down at some intermediate dimension or whether it can be followed up to d=3. If the latter, does it access the hedgehog-allowed O(3) model or something else? We use the numerical conformal bootstrap to study these questions by following the evolution of O(3) model from near dimension 2 to dimension 3. |
Thursday, March 9, 2023 12:42PM - 12:54PM |
T29.00007: Critical spin and charge fluctuations accompanying Kondo destruction in the particle-hole asymmetric Bose-Fermi Anderson model Ananth Kandala, Haoyu Hu, Qimiao Si, Kevin Ingersent Metallic quantum criticality is a central theme in a variety of strongly correlated systems. Recent experiments point to the puzzling existence of a singular charge response in heavy-fermion settings where the Landau framework of order-parameter fluctuations allows singularity only in the spin channel. A possible explanation lies in the Kondo-destruction scenario for beyond-Landau quantum criticality, which incorporates additional critical degrees of freedom [1-3]. Fluctuations between “large” and “small” Fermi surfaces lead to complete loss of quasiparticles in the quantum-critical regime. Here, we survey critical responses accompanying Kondo destruction in Bose-Fermi Anderson impurity models with a power-law bosonic bath having an exponent s < 1, and with a fermionic density of states that either vanishes at the Fermi energy as ρ(ε) ∝ |ε - εF|r with r > 0 or is featureless (corresponding to r = 0). We examine the nature of the critical fluctuations for different combinations of r and s, and compare the energy scales for fluctuations in the spin and charge channels. |
Thursday, March 9, 2023 12:54PM - 1:06PM |
T29.00008: Boundary effects in presence of dissipation in strongly correlated physics. Pradip Kattel, Natan Andrei, Parameshwar R Pasnoori When a quantum system is not isolated but coupled to an environment its effective dynamics involves loss and gain typically described by a non-Hermitian Hamiltonian. Such loss plays an important role in many quantum systems. For example, in this Noisy Intermediate-Scale Quantum Computing era, it is crucial to understand how robust the many-body phenomena are in presence of dissipation. An important class of such systems is described by PT-symmetric non-Hermitian where loss and gain are balanced. Here we present an exact solution of a PT-symmetric non-Hermitian quantum spin chain and explore the effects due to the non-unitary dynamics. The model describes a realistic system of interacting spinless fermions chain where particles can hop into or out of the system at the edges. We identify different phases where PT symmetry is spontaneously broken and unbroken. We show that the boundary edge modes are robust to the loss to over a range of parameters and compute several observables. |
Thursday, March 9, 2023 1:06PM - 1:18PM |
T29.00009: Neural-network quantum states in optical lattice with artificial magnetic flux Ahmet Keles, Mehmet O Oktel, Kadir Ceven Recently, few-leg ladder Hubbard models received considerable theoretical and experimental interest since they can be studied with established numerical methods, and complications of higher dimensional effects like gauge fields can be introduced optically in cold atom experiments. In this talk, we demonstrate the application of neural-network quantum states in the two-leg Bose-Hubbard ladder under strong synthetic magnetic fields using the restricted Boltzmann machine and feedforward neural networks. We show that variational neural networks can reliably predict the superfluid-Mott insulator transition in the strong coupling limit comparable with the accuracy of the density-matrix renormalization group. In the weak coupling limit, neural networks also diagnose other many-body phenomena like the vortex, chiral and biased-ladder phases. We will also present applications of neural-networks in finite two-dimensional systems with artificial magnetic fields. |
Thursday, March 9, 2023 1:18PM - 1:30PM Author not Attending |
T29.00010: Quantum Floquet engineering with an exactly solvable tight-binding chain in a cavity Dante M Kennes Recent experimental advances enable the manipulation of quantum matter by exploiting the quantum nature of light. However, paradigmatic exactly solvable models, such as the Dicke, Rabi or Jaynes-Cummings models for quantum-optical systems, are scarce in the corresponding solid-state, quantum materials context. Focusing on the long-wavelength limit for the light, here, we provide such an exactly solvable model given by a tight-binding chain coupled to a single cavity mode via a quantized version of the Peierls substitution. We show that perturbative expansions in the light-matter coupling have to be taken with care and can easily lead to a false superradiant phase. Furthermore, we provide an analytical expression for the groundstate in the thermodynamic limit, in which the cavity photons are squeezed by the light-matter coupling. In addition, we derive analytical expressions for the electronic single-particle spectral function and optical conductivity. We unveil quantum Floquet engineering signatures in these dynamical response functions, such as analogs to dynamical localization and replica side bands, complementing paradigmatic classical Floquet engineering results. Strikingly, the Drude weight in the optical conductivity of the electrons is partially suppressed by the presence of a single cavity mode through an induced electron-electron interaction. |
Thursday, March 9, 2023 1:30PM - 1:42PM |
T29.00011: Monte Carlo Simulations of the Disordered q-state Quantum Clock model Gaurav R Khairnar, Vishnu PK, Rajesh Narayanan, Thomas Vojta In this work, we consider the one-dimensional q-state quantum clock model with bond disorder. We map the quantum Hamiltonian to a two-dimensional classical q-state clock model with nearest neighbor interactions and quenched columnar random bond disorder. We study the classical model using large-scale Monte Carlo simulations. The clean q-state clock model is known to exhibit an intermediate quasi long-range ordered phase between paramagnetic and true long-range ordered phases for q ≥ 5. To identify critical temperature of the phase transitions as the disorder strength is varied, we consider the spin-wave stiffness. Spin-wave stiffness is a measure of free energy response to a twist in boundary conditions. It is a dimensionless observable for a 2D system. We identify the phase boundaries between the paramagnetic, quasi-long-range ordered and clock-ordered phases, and evaluate critical exponents as the disorder is varied. The model shows a non-trivial crossover from a weak to a strong disorder regime. |
Thursday, March 9, 2023 1:42PM - 1:54PM |
T29.00012: Highly entangled ground states in 2D Israel Klich, Zhao Zhang Hamiltonians with unusually high entanglement entropy in the ground states such as deformed colored Motzkin and Fredkin spin chains have been known for several years, however a proper high dimensional generalization of these have not been presented. In this talk I will discuss recent constructions of frustration free Hamiltonians in 2D whose ground states contain extensive entropy. The Hamiltonians are based on decorating height models, such as the six vertex model and the dimer model on the honeycomb lattice with additional degrees of freedom. The constructions feature a deformation parameter that can be tuned to exhibit new phase transitions in the entanglement behavior of the system, namely between perimeter (area) scaling, volume scaling and other intermediate possibilitie. |
Thursday, March 9, 2023 1:54PM - 2:06PM |
T29.00013: A Plane Defect in the 3D O(N) Model Abijith Krishnan, Max Metlitski It was recently found that the classical 3d O(N) model in the semi-infinite geometry supports an "extraordinary-log" boundary universality class, where the spin-spin correlation function on the boundary for spins separated by distance x falls off as (log x)-q. This universality class exists for a range 2 ≤ N < Nc; Monte-Carlo simulations indicate Nc > 3. In this work, we extend this analysis to the 3d O(N) model in an infinite geometry with a plane defect. We use renormalization group (RG) to show that in this case the extraordinary-log universality class is present for any finite N ≥ 2. We additionally show that the line of defect fixed points which is present at N = ∞ is lifted to the ordinary, special (no defect) and extraordinary-log universality classes by 1/N corrections in agreement with our RG analysis. Furthermore, at N = ∞ we show that the defect ``central charge" a = 0 is constant along the line of fixed points, in agreement with a theorem of Jensen and O'Bannon. Finally, we revisit the problem of the O(N) model in the semi-infinite geometry. We find evidence that at N = Nc the extraordinary and special fixed points annihilate and only the ordinary fixed point is left for N > Nc. |
Thursday, March 9, 2023 2:06PM - 2:18PM |
T29.00014: Tunable topological order of pseudo spins in semiconductor heterostructures Clemens Kuhlenkamp, Wilhelm Kadow, Atac Imamoglu, Michael Knap In this talk we discuss how frustrated Hubbard models can be realized in multi-layer moire structures. By identifying a synthetic layer spin degree of freedom, we can retain SU(2) symmetry, while controlling ring exchange processes with large external magnetic fields. This way, we can investigate various interacting Hofstadter states and their transitions. Remarkably, once the system turns Mott insulating we find exceptionally stable spin liquid phases which are induced by the magnetic field. As such fields are easily tunable in moire systems, our platform provides a promising route for inducing and controlling topologically ordered phases of matter. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700