Article
Physics, Multidisciplinary
M. Hachmann, Y. Kiefer, J. Riebesehl, R. Eichberger, A. Hemmerich
Summary: In this study, spin-polarized samples and spin mixtures of quantum degenerate fermionic atoms are prepared in selected excited Bloch bands of an optical checkerboard square lattice. The extreme band lifetimes above 10 s for the spin-polarized case reflect the suppression of collisions by Pauli's exclusion principle. The remarkable large values of about 1 s found for spin mixtures demonstrate the basis for exploring the physics of Fermi gases with two paired spin components in orbital optical lattices, including the regime of unitarity.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Zhipeng Sun
Summary: The Fermi surface topology plays a crucial role in the study of high-temperature superconductivity cuprates. The conventional method for determining the Fermi surface is not always reliable due to its sensitivity to noise or precision issues. In this study, a simple and specific notion, the derivative of the momentum distribution function with respect to the chemical potential, is proposed as a reliable approach to determine the Fermi surface.
Article
Optics
Gaurav Gyawali, Michael J. Lawler
Summary: This paper introduces an algorithm called ADAPT-VQE, an interpretable and adaptive variational quantum eigensolver, for preparing highly accurate ground states on small grids. This adaptive method outperforms nonadaptive VQE in terms of variational parameters, gate depth, and scalability with system size. The paper also demonstrates the application of adaptive variational methods in preparing excited states and Green's functions, and highlights their suitability for noisy intermediate-scale quantum devices.
Article
Optics
Aaron Merlin Mueller, Miklos Lajko, Florian Schreck, Frederic Mila, Jiri Minar
Summary: The study investigates species-selective cooling of a trapped SU(N) Fermi gas through entropy redistribution during adiabatic loading of an optical lattice, demonstrating improved cooling effects. Optimal performance is achieved when all atomic levels experience the same potential, outside of a specific dimple region. Specific quantitative discussions on achieving state-selective trapping in Sr-87 and Yb-173 using existing experimental techniques are provided.
Editorial Material
Chemistry, Physical
David A. Ruiz-Tijerina
Summary: Two studies investigate strongly correlated states of Bose-Fermi excitonic complexes in two different solid-state platforms, paving the way for tabletop quantum simulators.
Article
Optics
D. G. Suarez-Forero, D. W. Session, M. Jalali Mehrabad, P. Knuppel, S. Faelt, W. Wegscheider, M. Hafezi
Summary: The interplay between time-reversal symmetry breaking and strong light-matter coupling in two-dimensional gases brings intriguing aspects to polariton physics. This combination can lead to a polarization/spin-selective light-matter interaction in the strong coupling regime. We demonstrate circular-polarization dependence of the vacuum Rabi splitting by coupling a 2D gas in the quantum Hall regime to a microcavity, providing a quantitative understanding of the phenomenon.
Article
Optics
M. Pini, P. Pieri, R. Grimm, G. Calvanese Strinati
Summary: A detailed description of the phase diagram for a two-component unitary Fermi gas with mass and population imbalance is provided, aiming to offer quantitative benchmarks for the normal-to-superfluid phase transition in a temperature-polarization parameter space of a mass-imbalanced Fermi gas. The self-consistent t-matrix approach is adopted, known for accurately describing the thermodynamic properties of unitary Fermi gas with mass and population balance. The results serve as a guideline for ongoing experiments on heteronuclear Fermi mixtures.
Article
Multidisciplinary Sciences
Stasja Stanisic, Jan Lukas Bosse, Filippo Maria Gambetta, Raul A. Santos, Wojciech Mruczkiewicz, Thomas E. O'Brien, Eric Ostby, Ashley Montanaro
Summary: The authors successfully reproduced qualitative properties of the Fermi-Hubbard model using a VQE-based algorithm on a superconducting quantum processor, and employed various error-mitigation techniques to demonstrate the effectiveness of the algorithm.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Hiroki Akutsu, Scott S. Turner, Yasuhiro Nakazawa
Summary: This compound exhibits a phase transition at 160 K, forming a crucial structure with 1D Heisenberg antiferromagnetic behavior, while further cooling below 140 K leads to the formation of a spin ladder system.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Physics, Multidisciplinary
Yuta Murakami, Shintaro Takayoshi, Tatsuya Kaneko, Andreas M. Lauchli, Philipp Werner
Summary: We study the cold metastable states in one-dimensional photodoped Mott insulators and find that they exhibit spin, charge, and q-spin separation. The wave functions of these states can be expressed as IW) = IWcharge)IWspin)IWq-spin), similar to the Ogata-Shiba states in the doped Hubbard model. IWcharge) is determined by spinless free fermions, IWspin) by the isotropic Heisenberg model, and IWq-spin) by the XXZ model. We show that the q-pairing state has a central charge of 3 and the CDW phase has a central charge of 2, which we confirm numerically. Our study provides insights into the correlations between active degrees of freedom in photodoped strongly correlated systems.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yuchi He, David Pekker, Roger S. K. Mong
Summary: In the investigation of the phase diagram of the one-dimensional repulsive Hubbard model with mass imbalance, it was found that a triplet paired phase and two additional phases (crystal phase and trion phase) can occur. These phases were characterized using the Tomonaga-Luttinger liquid theory.
Article
Physics, Multidisciplinary
Zhenjiu Wang, Yuhai Liu, Toshihiro Sato, Martin Hohenadler, Chong Wang, Wenan Guo, Fakher F. Assaad
Summary: The study reveals new properties of the quantum spin Hall insulating state, paving the way for superconductivity through the condensation of skyrmions. Through simulations, it is confirmed that there is a direct transition between the quantum spin Hall insulator and an s-wave superconductor, with the ability to analyze dopings away from half-filling. This route to superconductivity has been proposed in the realm of twisted bilayer graphene.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Wenliang Zhang, Clio Efthimia Agrapidis, Yi Tseng, Teguh Citra Asmara, Eugenio Paris, Vladimir N. Strocov, Enrico Giannini, Satoshi Nishimoto, Krzysztof Wohlfeld, Thorsten Schmitt
Summary: This study investigates the evolution of spin excitations in hole-doped superconducting cuprates and confirms the close connection between spin excitations and short-range magnetic correlations.
NPJ QUANTUM MATERIALS
(2022)
Article
Multidisciplinary Sciences
Elham Sadeghi, Hamed Rezania
Summary: In this study, the transport properties of a two-dimensional Lieb lattice in the presence of magnetic field and spin-orbit coupling were investigated. The results showed that the increase of spin-orbit coupling led to a decrease in thermal conductivity, while the increase in temperature resulted in an increase in electrical and thermal conductivities. The temperature dependence of the Seebeck coefficient was also studied, revealing a positive thermopower in the presence of spin-orbit coupling.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Henry Yu, Sunny Gupta, Alex Kutana, Boris Yakobson
Summary: The electronic transport through a metal|semiconductor heterojunction is mainly determined by the Schottky barrier, with the pinning strength in 3D structures depending on the ratio between interface quantum capacitance and metal surface capacitance. In 2D structures, the interface dipole does not affect band alignment but influences the Schottky barrier and transport. The turn-on voltage and pinning strength in 2D contacts are affected by the physical parameter l/lambda(D), the ratio between interface width and thermal de Broglie wavelength.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Physics, Multidisciplinary
Benjamin M. Spar, Elmer Guardado-Sanchez, Sungjae Chi, Zoe Z. Yan, Waseem S. Bakr
Summary: In this study, we use an optical tweezer array with lithium-6 atoms to create an eight-site Fermi-Hubbard chain near half filling. By combining the tweezer array with a quantum gas microscope, we are able to detect individual sites. By minimizing disorder in energy offsets, we observe Mott insulators with strong antiferromagnetic correlations and measure the spin correlations, which lead us to estimate an upper bound of entropy per atom. We also demonstrate the flexibility of the tweezer platform by initializing atoms on one tweezer and observing tunneling dynamics across the array for different geometries.
PHYSICAL REVIEW LETTERS
(2022)
Article
Instruments & Instrumentation
Davis Garwood, Liyu Liu, Jirayu Mongkolkiattichai, Jin Yang, Peter Schauss
Summary: This study combines electromagnets and permanent magnets to extend the magnetic field of the electromagnet-based Zeeman slower, achieving nearly doubled loading rates of the magneto-optical trap without significant stray fields in the trapping region.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Editorial Material
Multidisciplinary Sciences
Alan Morningstar, Waseem Bakr
Article
Physics, Multidisciplinary
Jason S. Rosenberg, Lysander Christakis, Elmer Guardado-Sanchez, Zoe Z. Yan, Waseem S. Bakr
Summary: Measuring the statistical correlations of individual quantum objects is an excellent way to study complex quantum systems. This study demonstrates the detection of clustering correlations between individual molecules in an ultracold gas using a molecular quantum gas microscope, opening up new possibilities for studying interacting molecular gases in optical lattices with site-resolved analysis.
Article
Physics, Multidisciplinary
Zoe Z. Yan, Benjamin M. Spar, Max L. Prichard, Sungjae Chi, Hao-Tian Wei, Eduardo Ibarra-Garcia-Padilla, Kaden R. A. Hazzard, Waseem S. Bakr
Summary: Researchers have prepared high-filling two-component arrays of tens of fermionic 6Li atoms in optical tweezers, configuring the arrays in various two-dimensional geometries with negligible Floquet heating using a stroboscopic technique. By fully resolving the spin and density of individual sites, they were able to postselect near-zero entropy initial states for fermionic quantum simulation. They demonstrated all the building blocks needed to realize a programmable fermionic quantum simulator in a correlated state within a two-by-two tunnel-coupled Hubbard plaquette.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Xiqiao Wang, Ehsan Khatami, Fan Fei, Jonathan Wyrick, Pradeep Namboodiri, Ranjit Kashid, Albert F. Rigosi, Garnett Bryant, Richard Silver
Summary: In this study, Wang et al. demonstrate the control of electron ensembles and probing of many-body states in a 3 x 3 array of single/few-dopant quantum dots in silicon. By tuning lattice constants, they observe the finite-size analogue of a transition from metallic to Mott insulating behavior. These results open up new possibilities for simulating interacting fermionic models using engineered artificial lattices.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Condensed Matter
Rodrigo Alves Fontenele, Nathan Vasconcelos, Natanael Carvalho Costa, Thereza Paiva, Raimundo Rocha dos Santos
Summary: In this study, the effects of next-nearest-neighbor hoppings on the pairing properties of the attractive Hubbard model in a square lattice were examined. It was found that the existence of further hopping channels leads to an enhancement of the pairing correlations, increasing the ground-state order parameter Delta. At finite temperatures, this enhancement of pairing correlations leads to an increase in the critical temperature T-c.
Article
Multidisciplinary Sciences
Alexander Jarjour, G. M. Ferguson, Brian T. Schaefer, Menyoung Lee, Yen Lee Loh, Nandini Trivedi, Katja C. Nowack
Summary: The authors measured the superfluid response of exfoliated MoS2 using a micron-scale SQUID magnetometer and found magnetic properties in this superconductor. They directly measured the key property of the tunable, gate-induced superconducting state in MoS2 using a local magnetic probe. The observed behavior of the superfluid response in MoS2 significantly deviates from simple BCS-like behavior.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Andressa R. Medeiros-Silva, Natanael C. Costa, Thereza Paiva
Summary: This study investigates the repulsive Hubbard model on the kagome lattice using unbiased quantum Monte Carlo simulations. The thermodynamic properties, magnetic properties, and transport response of the system at finite temperatures and different values of the repulsive interaction are examined. The possible occurrence of adiabatic cooling and a metal-to-insulator transition at a finite interaction strength are discussed. The findings may guide future experiments on ultracold fermionic atoms on the kagome lattice.
Article
Materials Science, Multidisciplinary
Willdauany C. de Freitas Silva, Maykon Araujo, Sayantan Roy, Abhisek Samanta, Natanael de C. Costa, Nandini Trivedi, Thereza Paiva
Summary: This study calculates the Seebeck coefficient of two-dimensional Hubbard model on different geometries and reveals the effects of lattice bipartiteness, strong electronic correlations, and temperature variations near half-filling on the thermopower. The results indicate that electronic interactions can lead to unexpected behavior in thermopower for given fillings, which may vary depending on the geometry.
Article
Materials Science, Multidisciplinary
Rodrigo A. Fontenele, Natanael C. Costa, Raimundo R. dos Santos, Thereza Paiva
Summary: Recent experiments with ultracold fermionic atoms in optical lattices have provided a tunable and clean realization of the attractive Hubbard model (AHM) and have led to the investigation of various physical properties across the crossover between BCS and BEC couplings. Using determinant Quantum Monte Carlo (DQMC) studies, a detailed phase diagram for the critical superconducting temperature T, as well as two additional temperature scales, pairing T-p and degeneracy T-d, have been obtained. The distribution of doubly occupied sites in the momentum distribution function and the quasiparticle weight show distinct features on both sides of the BCS-BEC crossover, suggesting a crossover between Fermi- and non-Fermi liquid behaviors.
Article
Optics
Davis Garwood, Jirayu Mongkolkiattichai, Liyu Liu, Jin Yang, Peter Schauss
Summary: This study focuses on the Hubbard model on the triangular lattice, one of the simplest frustrated lattice geometries. By using a numerical linked-cluster expansion algorithm, the properties of the model are investigated. The results reveal interesting features that can assist in thermometry in ultracold atom quantum simulators and guide experimental searches for exotic quantum phases.
Article
Optics
Joseph C. Szabo, Nandini Trivedi
Summary: This study investigates competing entanglement dynamics between a one-dimensional Ising spin chain and an external ancilla qudit system. The results show that the entanglement entropy of the ancilla can track the dynamical phase transition in the underlying spin system. It is found that purely spin-spin entanglement metrics decay as the entanglement entropy of the ancilla increases. The study also introduces the concept of multipartite entanglement loss (MEL), which quantifies the effect of the ancilla on the development of spin-spin entanglement.
Article
Materials Science, Multidisciplinary
Abhisek Samanta, Anirban Das, Nandini Trivedi, Rajdeep Sensarma
Summary: In this study, we investigate the effects of thermal fluctuations on the two-particle spectral function of a disordered s-wave superconductor in two dimensions, focusing on the evolution of collective amplitude and phase modes. We find that thermal fluctuations soften the phase mode and allow for the survival of non-dispersive collective amplitude modes near zero momentum and the [pi, pi] point, even in the presence of disorder. Furthermore, scattering of thermally excited fermionic quasiparticles leads to the formation of a low-energy incoherent spectral weight that broadens and forms a strongly momentum-dependent background halo around the phase and amplitude collective modes.
