Current undergraduate students

Epitaxial Growth of Silicon Nanowires and Niobium Thin Films for Magnetic Resonance Force Microscopy

Michele Piscitelli

Magnetic Resonance Force Microscopy (MRFM) is an imaging technique enabling the acquisition of magnetic resonance images at nanometer scales. Single electron spin sensitivity has been demonstrated [1] and current MRFM research is focused on working towards achieving single nuclear spin sensitivity. In general, an MRFM setup requires a nano-scale source of high magnetic field gradients to modulate the sample spins and a cantilever-based detection scheme to measure their magnetic moment.

Robust quantum optimizer with full connectivity

Rakesh Tiwari, McGill University

Quantum phenomena have the potential to speed up the solution of hard optimization problems. For example quantum annealing, based on the quantum tunneling effect, has recently been shown to scale exponentially better with system size as compared with classical simulated annealing. However, current realizations of quantum annealers with superconducting qubits face two major challenges. First, the connectivity between the qubits is limited, excluding many optimization problems from a direct implementation.

Expected communication cost of distributed quantum tasks

Penghui Yao, University of Maryland, Baltimore

Data compression is a fundamental problem in quantum and classical information theory. A typical version of the problem is that the sender Alice receives a classical or quantum) state from some known ensemble and needs to transmit it to the receiver Bob with average error below some specified bound. We consider the case in which the message can have a variable length and goal is to minimise its expected length. For the classical case, this problem has a well-known solution given by the Huffman coding.

Quantum entanglement through the lens of computation and cryptography 

Henry Yuen, University of California at Berkeley

Quantum entanglement was once a philosophical peculiarity in physics — Einstein famously derided it as spooky action at a distance. Alongside wave/particle duality and the uncertainty principle, entanglement was just another bizarre feature of quantum mechanics. However, the study of quantum computation and quantum information has established entanglement as central to the story that connects quantum physics, computer science, and information theory.

Trapped-ion quantum logic with near-field microwave-driven gates

David Allcock, National Institute of Standards and Technology, Boulder

Hyperfine qubits in laser-cooled trapped atomic ions are one of the most promising platforms for general-purpose quantum computing. Magnetic field-insensitive ‘clock states’ and near-infinite lifetimes allow for minute-long memory coherence times as well as qubit frequencies that are in the convenient microwave domain [1]. Most work on these qubits has so far focussed on using lasers for gate operations, however there are several schemes that offer the prospect of performing all coherent operations using purely electronic methods [2,3].

Progress and challenges in designing a universal Majorana quantum computer

Torsten Karzig, Microsoft Research Station Q

I will discuss a promising design proposal for a scalable topological quantum computer. The qubits are envisioned to be encoded in aggregates of four or more Majorana zero modes, realized at the ends of topological superconducting wire segments that are assembled into superconducting islands with significant charging energy. Quantum information can be manipulated according to a measurement-only protocol, which is facilitated by tunable couplings between Majorana zero modes and nearby semiconductor quantum dots.

Carbon nanotube forest from energy conversion to MEMS devices and a laser based single sub 10nm particle analyzer: new developments in nanotechnology

​Mehran Vahdani, The University of British Columbia

Vertically aligned carbon nanotubes, so called CNT forests, have unique properties that make them excellent candidates in a wide variety of applications ranging from nanotechnology to electronics and photonics.

The mathematics of non-local games

William Slofstra, Institute for Quantum Computing

Non-local games are an important subject in quantum information. They provide relatively simple experimental scenarios for testing the axioms of quantum mechanics, and have been proposed for other practical applications, especially in device-independent cryptography. However, we do not know how to answer many of the basic mathematical questions about non-local games.

Quantum error-correction in black holes

Beni Yoshida, Perimeter Institute

It is commonly believed that quantum information is not lost in a black hole. Instead, it is encoded into non-local degrees of freedom in some clever way; like a quantum error-correcting code. In this talk, I will discuss recent attempts to resolve some paradoxes in quantum gravity by using the theory of quantum error-correction.

Atomic scale study of Dirac materials: graphene and topological insulator (Bi2Se3)

Ying Liu

Graphene and topological insulator Bi2Se3 are newly discovered Dirac materials with exotic physical and electronic properties. The molecular beam epitaxy (MBE) and in situ characterization at atomic scale of the materials are demonstrated in this talk[1][2]. Artificial defects of graphene are created by Ar for extending its functions. Their structural, electronic properties and charge state were studied by scanning tunneling microscopy (STM) and q-plus atomic force microscopy (q-plus AFM ), respectively.