Multi-Species Trapped Ion Modules for Large Scale Quantum Computers
(Free lunch served at 12:00 pm)
Optimal Circuit-level Decoding of Surface Codes
Surface codes exploit topological protection to increase error resilience in quantum computing devices and can in principle be implemented in existing hardware. They are one of the most promising candidates for active error correction, not least due to a polynomial time decoding algorithm which admits one of the highest predicted error thresholds.
Algorithms and Error Detection on a Programmable Ion Trap Quantum Computer
(Free lunch served at 12:00 pm)
Trapped ions are a highly advanced platform for implementing quantum circuits. They provide standard pairs of magnetic field insensitive "atomic clock" states as qubits with unsurpassed coherence times and optical schemes for near-unity preparation and measurement, as well as strong Coulomb interactions to generate entanglement.
Random tensor networks and holographic entanglement
Tensor networks provide a natural framework for exploring holographic dualities because their entanglement entropies automatically obey an area law. We study the holographic properties of networks of random tensors. We review several interesting structural features of the AdS/CFT correspondence and derive them in our model. Entropies of random tensor networks satisfy the Ryu-Takayanagi formula for all boundary regions, including corrections due to bulk entanglement.
Precision phase measurement using 2-mode squeezed states
(Free lunch served at 12:00pm)
In my presentation, I will talk about precision length measurement using 2-mode squeezed states. I will discuss several different measurements that we can perform to beat the standard quantum limit (SQL) for phase measurement using our two-mode squeezed states. The talk will also contain some of our recent data that shows phase measurements better than the SQL.
Quantum-security of commitment schemes and hash functions
Commitment schemes are a fundamental primitive in cryptography. Their security (more precisely the computational binding property) is closely tied to the notion of collision-resistance of hash functions. Classical definitions of binding and collision-resistance turn out too be weaker than expected when used in the quantum setting. We present strengthened notions (collapse-binding commitments and collapsing hash functions), explain why they are "better", and show how they be realized under standard assumptions.
Entangling semiconductor spin qubits via the Coulomb interaction
*Free lunch served at 12:00*
Qwire: A Core Language for Quantum Circuits
The QRAM model of quantum computing describes how a (hypothetical) quantum computer and a classical computer work together to produce sophisticated quantum algorithms. The classical computer handles the bulk of the computation and sends circuits to the quantum computer for execution. In this talk I will introduce the Qwire circuit language, which encodes circuits in a classical programming language of our choice and facilitates communication with an attached quantum computer.
What information theory teaches us on gravitational theory
Positive energy theorems play a fundamental role in general relativity. Recently, we found a new class of positive energy theorems using information inequalities such as the positivity and monotonicity of the relative entropy.
This and related applications of information theory are providing us new insights into gravitational theory.
Cold Atoms Inside an Optical Lattice
As a powerful tool, optical lattice makes it possible to study various areas of physics with cold atoms, such as modeling condensed matter systems, precision measurement, and quantum information. In this lecture I will talk about the basic concepts of optical lattices, the state-of-the-art techniques that people use to manipulate and probe atoms inside an optical lattice, and versatile applications exploring new and exciting physics.