Condensed Matter Seminar, Duke University

Regular time and place: Thursdays at 11:30am in Physics 298.
By clicking on calender data, you can import an event into your calendar. You can join the CMseminargroup mailing list to receive email announcements and reminders.

Upcoming events

2018/11/15   Fabio Altomare  (D-Wave Systems)calender data
"D-Wave quantum annealer as a quantum simulator"

D-Wave Systems builds superconducting quantum annealing processors that are primarily intended to be used for solving classical computation problems such as optimization and sampling. However, recent studies have shown how this computing platform can be used as a programmable quantum magnet that can be used to simulate physical systems relevant to the field of condensed matter physics. This lecture will provide a brief overview of D-Wave's technology, a summary of recently published quantum magnetism experiments, and a look ahead at next-generation quantum annealing processors.

[1]  A. D. King et al., Nature 560, 456 (2018)
[2]  R. Harris et al., Science 361, 162 (2018)

Host: Albert Chang, Thomas Barthel
2018/11/29   Arthur P. Ramirez  (UC Santa Cruz)calender data
"Transport in undoped Weyl semimetals and a new type of spin glass"

Two topics will be discussed. The first addresses transport in undoped Weyl semimetals (WSMs). Despite their name and the behavior of most WSMs, these materials should exhibit "semiconducting" temperature dependent resistivity, drho/dT<0, when undoped. We show that this form is obeyed in the rare-earth iridate pyrochlores, R2Ir2O7, in stoichiometric samples. We also show that for R = Yttrium, rho~1/T^4, consistent with a theory of charged impurity scattering, but extending into a temperature range where k_F l << 1, suggesting behavior of a "bad" WSM. The second topic will address an unusual spin glass, pseudobrookite Fe2TiO5 in which an Ising anisotropy develops due to interactions. This presents a second example of "quasi-spin" glass.

Host: Harold Baranger
2018/12/06   Luiz Henrique Bugatti Guessi  (Universidade de Sao Paulo, Duke)calender data
"Correlation effects in the emergence of bound states in the continuum"

Bound states in the continuum (BICs) are states with localized wave-functions even though lying in the continuum. Here, we explore theoretically the emergence of BICs in a system comprising two identical quantum dots side-coupled to a quantum wire. The dots are symmetrically coupled to the site at the center of the wire and to its nearest neighbors. Taking advantage of the parity symmetry, we work with the bonding and the anti-bonding (AB) levels resulting from the symmetric and antisymmetric combinations of the dot levels. Based on the two-impurity Anderson Hamiltonian and the numerical renormalization group method, our results show that the AB orbital is a BIC in the non-interacting limit. The AB orbital is broadened due the spin-spin and spin-flip interactions between the two orbitals. In addition, if the coupling is particle-hole asymmetric, the magnetic moments of the dots can form a triplet or a singlet state due to the RKKY interaction, affecting the formation of the Kondo cloud. In the strong asymmetric coupling limit, the AB orbital is reduced to a singly occupied level that is decoupled from the continuum, i.e., a bound spin states in the continuum.
2018/12/13   Journal club ft. Xin Zhangcalender data
"Phase transitions in driven-dissipative quantum optical systems"

[1]  P.D. Drummond and D.F. Walls, J. Phys. A: Math. Gen. 13, 725 (1980)
[2]  W. Casteels, F. Storme, A. Le Boité, and C. Ciuti, Phys. Rev. A 93, 033824 (2016)
[3]  W. Casteels, R. Fazio, and C. Ciuti, Phys. Rev. A 95, 012128 (2017)
[4]  T. Fink, A. Schade, S. Höfling, C. Schneider, A. Imamoglu, Nature Physics 14, 365 (2018)
2019/02/07   Elizabeth L, Green  (Helmholtz-Zentrum Dresden-Rossendorf)calender data
title and abstract t.b.a.

Host: Sara Haravifard

Past events

2018/11/08 Nicholas P. Butch  (NIST, UMD College Park)calender data
"Spin polarized half-gapped superconductivity"
2018/10/11 Seyed M. Koohpayeh  (Johns Hopkins University)calender data
"Development, synthesis, and bulk crystal growth of novel/quantum materials"
2018/05/10 Oleg L. Berman  (City University of New York)calender data
"Exciton Bose-Einstein condensation and superfluidity in two-dimensional nanomaterials"
2018/05/07 Hannes Pichler  (Harvard University),   Unusual weekday: Monday!calender data
"Universal photonic quantum computation via time-delayed feedback"
2018/05/01 Chun Ning (Jeanie) Lau  (Ohio State University),   Unusual weekday: Tuesday!calender data
"Spin, charge and heat transport in low-dimensional materials"
2018/04/26 Adolfo del Campo  (University of Massachusetts Boston)calender data
"Tailoring the dynamics of isolated and open quantum systems"
2018/04/19 Charles L. Kane  (University of Pennsylvania)calender data
"Topological superconductivity from Majorana to Fibonacci"
2018/04/17 Dan Shahar  (Weizmann Institute of Science),   Unusual weekday: Tuesday!calender data
"Hot superconductors and cold insulators"
2018/04/10 Manuel Houzet  (Université Grenoble Alpes and CEA),   Unusual weekday: Tuesday!calender data
"Non-equilibrium quasi-particles in disordered superconductors"
2018/03/29 Journal club ft. Anne Draeloscalender data
"Superconductivity and Mott insulating behavior in twisted bilayer graphene"
2018/03/22 Carlos A. R. Sa de Melo  (Georgia Tech)calender data
"Color superfluidity of neutral ultracold fermions in the presence of color-orbit and color-flip fields"
2018/03/15 Journal club ft. Xin Zhangcalender data
"Variational approach to non-equilibrium quantum impurity problems"
2018/02/22 James R. Williams  (University of Maryland, College Park)calender data
"Using Josephson junctions to probe quantum materials"
2018/02/15 Journal club ft. Gu Zhangcalender data
"Geometric phase at quantum phase transitions"
2018/01/11 Sho Yaida  (Duke University)calender data
"Novel phase transition within amorphous solids"
2017/12/07 Thomas Barthel  (Duke University)calender data
"Fractal structures in the phase diagram of the honeycomb-lattice quantum dimer model"
2017/11/16 Aashish Clerk  (University of Chicago)calender data
"Photonic analogues of topological superconductors"
2017/10/26 Dmitri Khveshchenko  (UNC Chapel Hill)calender data
"Thickening and sickening the Sachdev-Ye-Kitaev model"
2017/10/12 Giuseppe Calajo  (TU Wien)calender data
"Atom-light interactions in slow-light waveguide QED"
2017/09/21 Kirill Shtengel  (University of California Riverside)calender data
"Designer non-Abelian anyons and exotic quantum circuitry"
2017/09/07 Elbio R. A. Dagotto  (University of Tennessee and ORNL)calender data
"Computational studies of iron-based high critical temperature superconductors"
2017/09/05 Václav Janiš  (Charles University in Prague, Academy of Sciences of the Czech Republic),   Unusual weekday: Tuesday!calender data
"Quantum dot attached to superconducting leads: Andreev bound states and 0-pi transition"
2017/05/25 Journal club ft. Gu Zhangcalender data
"Transport through many-terminal Majorana islands"
2017/05/11 Journal club ft. Xin Zhangcalender data
"Topology of density matrices"
2017/04/20 Zhenzhong Shi  (National High Magnetic Field Lab)calender data
"Hidden order of Cooper pairs in a striped cuprate at high magnetic fields"
2017/04/06 Subir Sachdev  (Harvard University)calender data
"Confinement transitions of Ising gauge theories"
2017/03/30 Leo Fang  (Duke University)calender data
"Non-Markovian dynamics of a qubit due to photon scattering in a waveguide"
2017/03/23 Francesco Ciccarello  (University of Palermo, NEST, Duke)calender data
"Quantum 'non-Markovianity': new definitions and some recent developments"
2017/02/16 Po-Hao Huang  (Boston University)calender data
"Coupled spin-1/2 ladders as microscopic models for non-Abelian chiral spin liquids"
2017/01/12 Dong Liu  (Microsoft Station Q)calender data
"Majorana Search: Challenges and opportunities"
2016/12/01 Alexander Kemper  (NC State University)calender data
"Understanding complex materials using nonequilibrium spectroscopy: What can theory tell?"
2016/11/22 Informal seminar ft. Ben Lawson  (University of Michigan),   Unusual time: Tuesday, 1:30pm!calender data
"Torque magnetometry on topological superconductor candidate doped Bi2Se3"
2016/11/22 Informal seminar ft. Elbio R. A. Dagotto  (University of Tennessee and ORNL),   Unusual time: Tuesday, 9:30am!calender data
2016/11/15 Kin Chung Fong  (Raytheon BBN Technologies),   Unusual weekday: Tuesday!calender data
"Listening to the noise of Dirac fluid in graphene"
2016/11/10 Shiwei Zhang  (College of William and Mary)calender data
"Computing electron correlation effects: an auxiliary-field perspective"
2016/10/17 Denis Ullmo  (LPTMS, Université Paris Sud),   Unusual weekday: Monday!calender data
"Schrödinger approach to Mean Field Games"
2016/10/11 Yoshitomo Kamiya  (CMT Laboratory, RIKEN),   Unusual weekday: Tuesday!calender data
"Multiferroics by design with frustrated molecular magnets"
2016/09/29 Carlos J. Bolech  (University of Cincinnati)calender data
"Consistency between bosonization and nonequilibrium transport setups"
2016/09/22 Siyuan Dai  (UC San Diego)calender data
"Hyperbolic phonon polaritons in hexagonal boron nitride"
2016/07/18 Huaixiu Zheng  (Yale University),   Unusual weekday: Monday!calender data
"Quantum state smoothing for single microwave photon detection"
2016/04/07 Waseem S. Bakr  (Princeton University)calender data
"Strongly-interacting fermionic superfluids: spin-imbalance, lower dimensionality and topological defects"
2016/03/24 Konstantin Matveev  (Argonne National Lab)calender data
"Electrical and thermal transport in inhomogeneous Luttinger liquids"
2016/03/21 Hao Zhang  (TU Delft),   Unusual weekday: Monday!calender data
"Majorana zero modes in InSb nanowires"
2016/03/10 Eduardo Novais  (Universidade Federal do ABC, Brazil)calender data
"Fidelity of a quantum state protected by the surface code at finite temperatures"
2016/02/29 Journal club ft. Moritz Binder,   Unusual weekday & place: Monday, Physics 205!calender data
"Identification of Hamiltonians and Liouvillians"
2016/02/25 Adriana Moreo  (University of Tennessee, ORNL)calender data
"Robust nematic state in electron-doped pnictides induced by isotropic quenched disorder"
2016/02/11 Arnab Banerjee  (Oak Ridge National Laboratory)calender data
"In search of exotic fermions in spin-liquids - the case of a-RuCl3"
2016/01/21 Gu Zhang  (Duke University)calender data
"Rescuing a quantum phase transition with quantum noise"
2015/12/07 Journal club ft. Moritz Binder,   Unusual weekday: Monday!calender data
"Photonic quantum circuits with time delays"
2015/11/19 Daniel Silevitch  (University of Chicago, Caltech)calender data
"Tunable ground states in a model quantum magnet"
2015/11/12 Catherine Marcoux  (Duke University)calender data
"Limit-periodic structures: self-assembly and sparse vibrational modes"
2015/10/22 Adrian E. Feiguin  (Northeastern University, Boston)calender data
"Building and understanding magnetic nano-structures, one atom at a time"
2015/10/08 Christopher Wilson  (University of Waterloo)calender data
"Quantum electrodynamics in 1D using a superconducting artificial atom"
2015/10/01 François Amet  (Appalachian State University)calender data
"Superconductivity in the quantum Hall regime"
2015/09/24 Journal club ft. Gu Zhangcalender data
"Fate of the Kondo effect and impurity quantum phase transitions through the lens of fidelity susceptibility"
2015/09/10 Journal club ft. Leo Fangcalender data
"A chemical potential for light"
2015/09/03 Journal club ft. Anne Watsoncalender data
"Hot-carrier Seebeck effect: Diffusion and remote detection of hot carriers in graphene"

have a nice day!