## Condensed Matter Seminar,
Regular time and place: Thursdays at 11:30am in Physics 298. |

2018/05/10 |
Oleg L. Berman (City University of New York)"Exciton Bose-Einstein condensation and superfluidity in two-dimensional nanomaterials"This talk reviews the theoretical studies of the Bose-Einstein condensation (BEC) and superfluidity of indirect excitons and microcavity polaritons in quasi-two-dimensional (quasi-2D) van der Waals nanomaterials such as graphene, phosphorene, and transition metal dichalcogenide (TMDC) heterostructures. Indirect excitons are the Coulomb-bound pairs of electrons and holes confined to different parallel monolayers of a layered planar nanomaterial structure. It has been shown that the indirect excitons in gapped bilayer graphene can form BEC and experience superfluidity [1]. The high-T superfluidity of the two-component weakly-interacting Bose gas of the A-type and B-type indirect excitons in the TMDC heterostructures is proposed [2,3]. The critical temperature and superfluid velocity of the indirect excitons in a bilayer phosphorene nanostructure is shown to be anisotropic, dependent strongly on the particular direction of the exciton propagation [4]. Also analyzed are the effects of high magnetic fields on the BEC and superfluidity of exciton polaritons formed by the direct excitons in gapped monolayer graphene embedded in an optical microcavity to show that the polariton BEC can be manipulated by an external magnetic field [5], whereas the superfluid behavior can be controlled by changing the graphene gap [6]. These results open up new avenues for the experimental realization of the exciton BEC and superfluidity phenomena as well as their practical applications in optoelectronics [7]. [1] O. L. Berman, R. Ya. Kezerashvili, and K. Ziegler, PRB 85, 035418 (2012) [2] O. L. Berman and R. Ya. Kezerashvili, PRB 93, 245410 (2016) [3] O. L. Berman and R. Ya. Kezerashvili, PRB 96, 094502 (2017) [4] O. L. Berman, G. Gumbs, and R. Ya. Kezerashvili, PRB 96, 014505 (2017) [5] O. L. Berman, R. Ya. Kezerashvili, and Yu. E. Lozovik, PRB 80, 115302 (2009) [6] O. L. Berman, R. Ya. Kezerashvili, and K. Ziegler, PRB 86, 235404 (2012) [7] D. W. Snoke and J. Keeling, Physics Today 70, 54 (2017) Host: Harold Baranger |

2018/05/07 |
Hannes Pichler (Harvard University), Unusual weekday: Monday!"Universal photonic quantum computation via time-delayed feedback" | |

2018/05/01 |
Chun Ning (Jeanie) Lau (Ohio State University), Unusual weekday: Tuesday!"Spin, charge and heat transport in low-dimensional materials" | |

2018/04/26 |
Adolfo del Campo (University of Massachusetts Boston)"Tailoring the dynamics of isolated and open quantum systems" | |

2018/04/19 |
Charles L. Kane (University of Pennsylvania)"Topological superconductivity from Majorana to Fibonacci" | |

2018/04/17 |
Dan Shahar (Weizmann Institute of Science), Unusual weekday: Tuesday!"Hot superconductors and cold insulators" | |

2018/04/10 |
Manuel Houzet (Université Grenoble Alpes and CEA), Unusual weekday: Tuesday!"Non-equilibrium quasi-particles in disordered superconductors" | |

2018/03/29 |
Journal club ft.
Anne Draelos"Superconductivity and Mott insulating behavior in twisted bilayer graphene" | |

2018/03/22 |
Carlos A. R. Sa de Melo (Georgia Tech)"Color superfluidity of neutral ultracold fermions in the presence of color-orbit and color-flip fields" | |

2018/03/15 |
Journal club ft.
Xin Zhang"Variational approach to non-equilibrium quantum impurity problems" | |

2018/02/22 |
James R. Williams (University of Maryland, College Park)"Using Josephson junctions to probe quantum materials" | |

2018/02/15 |
Journal club ft.
Gu Zhang"Geometric phase at quantum phase transitions" | |

2018/01/11 |
Sho Yaida (Duke University)"Novel phase transition within amorphous solids" | |

2017/12/07 |
Thomas Barthel (Duke University)"Fractal structures in the phase diagram of the honeycomb-lattice quantum dimer model" | |

2017/11/16 |
Aashish Clerk (University of Chicago)"Photonic analogues of topological superconductors" | |

2017/10/26 |
Dmitri Khveshchenko (UNC Chapel Hill)"Thickening and sickening the Sachdev-Ye-Kitaev model" | |

2017/10/12 |
Giuseppe Calajo (TU Wien)"Atom-light interactions in slow-light waveguide QED" | |

2017/09/21 |
Kirill Shtengel (University of California Riverside)"Designer non-Abelian anyons and exotic quantum circuitry" | |

2017/09/07 |
Elbio R. A. Dagotto (University of Tennessee and ORNL)"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!"Quantum dot attached to superconducting leads: Andreev bound states and 0-pi transition" | |

2017/05/25 |
Journal club ft.
Gu Zhang"Transport through many-terminal Majorana islands" | |

2017/05/11 |
Journal club ft.
Xin Zhang"Topology of density matrices" | |

2017/04/20 |
Zhenzhong Shi (National High Magnetic Field Lab)"Hidden order of Cooper pairs in a striped cuprate at high magnetic fields" | |

2017/04/06 |
Subir Sachdev (Harvard University)"Confinement transitions of Ising gauge theories" | |

2017/03/30 |
Leo Fang (Duke University)"Non-Markovian dynamics of a qubit due to photon scattering in a waveguide" | |

2017/03/23 |
Francesco Ciccarello (University of Palermo, NEST, Duke)"Quantum 'non-Markovianity': new definitions and some recent developments" | |

2017/02/16 |
Po-Hao Huang (Boston University)"Coupled spin-1/2 ladders as microscopic models for non-Abelian chiral spin liquids" | |

2017/01/12 |
Dong Liu (Microsoft Station Q)"Majorana Search: Challenges and opportunities" | |

2016/12/01 |
Alexander Kemper (NC State University)"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!"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! | |

2016/11/15 |
Kin Chung Fong (Raytheon BBN Technologies), Unusual weekday: Tuesday!"Listening to the noise of Dirac fluid in graphene" | |

2016/11/10 |
Shiwei Zhang (College of William and Mary)"Computing electron correlation effects: an auxiliary-field perspective" | |

2016/10/17 |
Denis Ullmo (LPTMS, Université Paris Sud), Unusual weekday: Monday!"Schrödinger approach to Mean Field Games" | |

2016/10/11 |
Yoshitomo Kamiya (CMT Laboratory, RIKEN), Unusual weekday: Tuesday!"Multiferroics by design with frustrated molecular magnets" | |

2016/09/29 |
Carlos J. Bolech (University of Cincinnati)"Consistency between bosonization and nonequilibrium transport setups" | |

2016/09/22 |
Siyuan Dai (UC San Diego)"Hyperbolic phonon polaritons in hexagonal boron nitride" | |

2016/07/18 |
Huaixiu Zheng (Yale University), Unusual weekday: Monday!"Quantum state smoothing for single microwave photon detection" | |

2016/04/07 |
Waseem S. Bakr (Princeton University)"Strongly-interacting fermionic superfluids: spin-imbalance, lower dimensionality and topological defects" | |

2016/03/24 |
Konstantin Matveev (Argonne National Lab)"Electrical and thermal transport in inhomogeneous Luttinger liquids" | |

2016/03/21 |
Hao Zhang (TU Delft), Unusual weekday: Monday!"Majorana zero modes in InSb nanowires" | |

2016/03/10 |
Eduardo Novais (Universidade Federal do ABC, Brazil)"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!"Identification of Hamiltonians and Liouvillians" | |

2016/02/25 |
Adriana Moreo (University of Tennessee, ORNL)"Robust nematic state in electron-doped pnictides induced by isotropic quenched disorder" | |

2016/02/11 |
Arnab Banerjee (Oak Ridge National Laboratory)"In search of exotic fermions in spin-liquids - the case of a-RuCl3" | |

2016/01/21 |
Gu Zhang (Duke University)"Rescuing a quantum phase transition with quantum noise" | |

2015/12/07 |
Journal club ft.
Moritz Binder, Unusual weekday: Monday!"Photonic quantum circuits with time delays" | |

2015/11/19 |
Daniel Silevitch (University of Chicago, Caltech)"Tunable ground states in a model quantum magnet" | |

2015/11/12 |
Catherine Marcoux (Duke University)"Limit-periodic structures: self-assembly and sparse vibrational modes" | |

2015/10/22 |
Adrian E. Feiguin (Northeastern University, Boston)"Building and understanding magnetic nano-structures, one atom at a time" | |

2015/10/08 |
Christopher Wilson (University of Waterloo)"Quantum electrodynamics in 1D using a superconducting artificial atom" | |

2015/10/01 |
François Amet (Appalachian State University)"Superconductivity in the quantum Hall regime" | |

2015/09/24 |
Journal club ft.
Gu Zhang"Fate of the Kondo effect and impurity quantum phase transitions through the lens of fidelity susceptibility" | |

2015/09/10 |
Journal club ft.
Leo Fang"A chemical potential for light" | |

2015/09/03 |
Journal club ft.
Anne Watson"Hot-carrier Seebeck effect: Diffusion and remote detection of hot carriers in graphene" |

have a nice day!