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USC Quantum Information and Condensed Matter Physics Seminars |
For more information contact Stephan Haas (condensed matter) (213) 740-4528, or Daniel Lidar (quantum information) (213) 740-0198.
Federico Piazza (Perimeter Institute)
Particle detector models, entropy and localization in semiclassical gravity
I will discuss localization in QFT from different perspectives and the possible implications that a novel view on localization may have on our present understanding of semiclassical gravity.
Sep 15
Radu Ionicioiu (Bristol)
Generalized parity measurements
Measurements play an important role in quantum computing (QC), by either providing the nonlinearity required for two-qubit gates (linear optics QC), or by implementing a quantum algorithm using single-qubit measurements on a highly entangled initial state (cluster state QC). Parity measurements can be used as building blocks for preparing arbitrary stabilizer states, and, together with 1-qubit gates are universal for quantum computing. Here we generalize parity gates by using a higher dimensional (qudit) ancilla. This enables us to go beyond the stabilizer/graph state formalism and prepare other types of multi-particle entangled states. The generalized parity module introduced here can prepare in one-shot, heralded by the outcome of the ancilla, a large class of entangled states, including GHZ_n, W_n, Dicke states D_{n,k}, and, more generally, certain sums of Dicke states, like G_n states used in secret sharing. For W_n states it provides an exponential gain compared to linear optics based methods.
Sep 19
Kirill Shtengel (UCR)
Interferometry of non-Abelian anyons
Topologically-ordered phases supporting excitations with non-Abelian braiding statistics are expected to occur at several observed fractional quantum Hall plateaux. These states are of particular interest as they may provide a platform for topological quantum computation. Interferometric experiments are likely to play a crucial role in both determining the non-Abelian nature of these states and in their potential applications for quantum computing. I will discuss interferometric experiments designed to detect such non-Abelian quasiparticle statistics -- one of the hallmark characteristics of the Moore-Read and Read-Rezayi states, which are likely candidates for the observed fractional quantum Hall plateaux at $\nu=5/2$ and $12/5$ respectively. Aside from their potential utility for experimental verification of non-Abelian anyonic statistics, such interferometric experiments would provide the most promising route to qubit read-out in a topological quantum computation.
Sep 26
Tadashi Hasebe (Kobe University)
Field Theory of Multiscale Plasticity and Its Applications
This lecture presents firstly the features of the field theory of plasticity which can deal with evolutions of inhomogeneities in any scale levels and their interactions in a rigorous manner, together with its implementation into crystalline plasticity-based constitutive equation. Secondly new notions about ^Óduality^Ô between stress and strain field fluctuations, global-local scale free-like cooperation in polycrystalline elasto-plasticity, and theoretical inter-scale coupling based on interaction field formalism will be discussed. Also mentioned lastly will be three on-going projects, i.e., on (1)control of fatigue for Cu-added steels, (2)high precision valuation of springback of high strength steels for automotive bodies and (3)prediction of long-term degradation of high Cr steels for FBR (fast breeder reactor) by showing intriguing experimental observations and some key mechanisms.
Oct 3
Andreas Schnyder (KITP UCSB)
postponed
TBA
Oct 7
Rosa DiFelice (National Institute for the Physics of Matter, Italy)
Computational investigation of DNA-derivatives for nano-electronics
The unique self-assembling and recognition properties of DNA make it appealing for the realization of DNA-based nano-electronics. However, contoversial experimental data reveal a complex situation. To improve the significance of the data, two concurrent options are presently followed: (1) improve the measurement setup; (2) look for alternative DNA-based candidates. The latter can be based on alterations of either the nucleobase chemistry or the helical motif. I will illustrate how ab initio electronic structure calculations and molecular dynamics simulations can elucidate the electronic and structural properties of native and modified DNA structures. In particular, I will show results and discussion about density-funtional-theory (DFT) and molecular dynamics studies of G4-DNA, time-dependent DFT stuies of DNA and xDNA, DFT studies of M-DNA and natural DNA.
Oct 10
Igor Beloborodov (Calstate Northridge)
Artificial Nanosolids
Artificial nanosolids, arrays of nanoscale grains interacting with each other through electron tunneling, offer rich new horizons of novel macroscopic behavior emerging from nanoscale structure and dynamics. Fundamental microscopic phenomena such as Coulomb correlation, disorder and coherence produce dramatically new and programmable bulk behavior when mediated by nanoscale granular structure. Each building block of these new materials can be viewed as a tiny cluster of atoms of metallic, semiconducting or superconducting elements. These clusters are not as small as molecules but not as large as macroscopic objects. I will review our progress made in the last several years in understanding the properties of artificial nanosolids. In particular, I will discuss the following topics: (1) Introduction to physics of artificial nanosolids, (2) Novel transport regimes, (3) The phase diagram of artificial nanosolids, (4) Future opportunities. Reference: I. Beloborodov et al., Reviews of Modern Physics, 79, 469 (2007).
Nov 7
Jason Alicea (Caltech)
TBA
TBA
Nov 14
Gerd Bergmann (USC)
TBA
TBA
Nov 27
Andreas Schnyder (KITP UCSB)
TBA
TBA
Dec 12
Olexei Motrunich (Caltech)
TBA
TBA
Jan 19
Roman Orus Lacort (University of Queensland)
TBA
TBA
USC 
Caltech
UCLA ITP