Future graduate students

Scalable surface ion traps for high-fidelity quantum operations

Peter Maunz, Sandia National Laboratories

Trapped ion systems can be used to implement quantum computation as well as quantum simulation. To scale these systems to the number of qubits required to solve interesting problems in quantum chemistry or solid state physics, the use of large multi-zone ion traps has been proposed [1]. Microfabrication enables the realization of surface electrode ion traps with complex electrode structures.

Quantum Gravity, Tensor Network, and Holographic Entanglement Entropy

Muxin Han, Florida Atlantic University

The relation between nonperturbative Quantum Gravity and tensor network is explored from the perspectives of bulk-boundary duality and holographic entanglement entropy. We find that the quantum gravity states in a space Σ with boundary ∂Σ is an exact holographic mapping. The tensor network, understood as the boundary quantum state, is the output of the exact holographic mapping emerging from a coarse graining procedure of quantum gravity state.

Superconductivity in single-layer NbSe2

Kin Fai Mak, Pennsylvania State University

The discovery of graphene has stimulated not only the field of carbon nanoelectronics, but also studies of novel electronic phenomena in a wide range of atomically thin van der Waals’ materials. In this talk, I will discuss our recent effort in the isolation of a single layer of niobium diselenide (NbSe2), a new non-centrosymmetric superconductor.

The puzzle of genuine multiparticle interference

Sascha Agne, IQC

Two recent experiments demonstrate access to a new realm of quantum phenomena called genuine multiparticle interference. For three photons this means that interference between all three photons is observed while, simultaneously, neither pairs nor single photons display interference.

Rigorous RG algorithms and area laws for low energy eigenstates in 1D

Thomas Vidick, California Institute of Technology

One of the central challenges in the study of quantum many-body systems is the complexity of simulating them on a classical computer. We give a new algorithm for finding low energy states for 1D systems, based on a rigorously justified RG type transformation.

Entropy measurement in quantum systems

Dr. Mohammad Ansari, Peter Grünberg Institute, and Jülich-Aachen Research Alliance Institute (JARA)

Entropy is an important information measure. A complete understanding of entropy flow will have applications in quantum thermodynamics and beyond; for example it may help to identify the sources of fidelity loss in quantum communications and methods to prevent or control them. Being nonlinear in density matrix, its evaluation for quantum systems requires simultaneous evolution of more-than-one density matrix.

Optical manipulation of polariton in semiconductor microstructures

Félix Marsault, French National Center for Scientific Research

Cavity polaritons are bosonic quasiparticles arising from the strong coupling between photons and excitons. They can massively occupy a single quantum state in the regime of polariton lasing [1], showing particular properties such as long coherence times [1], long range spatial coherence [1] and a linearly polarized emission [1,2,3]. Moreover, they possess strong excitonic nonlinearities and thus provide a new platform for elliptical photonic manipulation, with the demonstration of a polariton spin switch [4], polariton transistors [5] and the proposal of other proof-of-principle operations for elliptical integrated logic circuits [6].

Tip induced superconductivity at mesoscopic point contacts on topological semimetals

Leena Aggarwal, Indian Institute of Science Education and Research, Mohali

I will present the observation of a new phase of matter, tip-induced superconductivity (TISC), that emerges only under mesoscopic metallic point contacts on topologically non-trivial semimetals like a 3-D Dirac semimetal Cd3As2, and a Weyl semimetal, TaAs. From theoretical considerations, it is believed that such semimetals exist near topological phase boundaries.

The Power of Randomized and Quantum Computation

Shalev Ben-David, Massachusetts Institute of Technology

Randomized and quantum computing offer potential improvements over deterministic algorithms, and challenge our notion of what should be considered efficient computation. A fundamental question in complexity theory is to try to understand when these resources help; on which tasks do randomized or quantum algorithms outperform deterministic ones?

In this talk, I will describe some of my work investigating this question, primarily in the query complexity (blackbox) model.