Events

Short film festival + public lecture by Martin Laforest

Join us for a night of film and science. The Institute for Quantum Computing has partnered with the Centre for Quantum Technologies in Singapore to host a festival for quantum-inspired films. The screening of the top 10 short films will be followed by a lecture by Senior Manager, Scientific Outreach, Martin Laforest about the applications of quantum devices. He will delve into what we know quantum devices will be used for (that will affect everyone) and where researchers are hoping they will be used in the future.

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.

Harnessing quantum entanglement 

Laura Mancinska, University of Bristol 

The phenomenon of entanglement is one the key features of quantum mechanics. It can be used to attain functionality lying beyond the reach of classical technologies. In practice, however, finding the best way of harnessing entanglement for a given task is extremely challenging and one is often forced to resort to ad hoc methods. The mathematical structure of entanglement- enabled strategies is poorly understood and many basic questions remain open. This lack of understanding has prevented us from fully exploiting the advantages that entanglement can offer for operational tasks.

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.

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.

Harnessing quantum systems with long-range interactions

Zhexuan Gong, University of Maryland, College Park

A distinctive feature of atomic, molecular, and optical systems is that interactions between particles are often long-ranged. Together with control techniques from quantum optics, these long-range interacting systems could be harnessed to achieve faster quantum information processing and to simulate novel quantum many-body phenomena. A

Quantum Entanglement, Sum-of-Squares and the Log-Rank Conjecture

Pravesh Kothari, Princeton University

This talk will be about a sub-exponential time algorithm for the Best Separable State (BSS) problem. For every constant \eps>0, we give an exp(\sqrt(n) \poly log(n))-time algorithm for the 1 vs 1-\eps BSS problem of distinguishing, given an n^2 x n^2 matrix M corresponding to a quantum measurement, between the case that there is a separable (i.e., non-entangled) state \rho that M accepts with probability 1, and the case that every separable state is accepted with probability at most 1-\eps.

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.

Fabrication of Diamond Based Fabry-Perot Cavities: Boring is beautiful

Madelaine Liddy, IQC

Nitrogen-vacancy (NV) centers in diamond are promising candidates for acting as the nodes in a quantum network. Previous work has demonstrated the entanglement between two NV centers over a distance of 1.3km for the loophole-free bell test in 2015.

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].