# Welcome to the Institute for Quantum Computing

## News

Wednesday, March 22, 2023

## Mitigating errors in superconducting quantum circuits to pave the way for future quantum computers

With the quantum age on the horizon, scientists are working to develop quantum computers that will have a processing speed exponentially faster than today’s most advanced supercomputer. Building a useful quantum computer is one of the great engineering challenges of our time. In all implementations, qubits that are reliable, stable, and scalable are essential in this endeavor.

Monday, March 20, 2023

## IQC Celebrates National Engineering Month

March is National Engineering Month in Canada! IQC is celebrating engineering excellence by recognizing some of our amazing members and their achievements.

Tuesday, March 14, 2023

## IQC researchers bring theory to reality with a new experiment

IQC researchers Dr. Raymond Laflamme, Dr. Eduardo Martín-Martínez, Dr. Nayeli Rodríguez-Briones and Dr. Hemant Katiyar experimentally tested the impact of entanglement between particles to extract energy from a vacuum state.

## Events

Monday, April 3, 2023 10:00 am - 11:00 am EDT

## Tailoring quantum error correction for structured noise

### IQC Special Seminar, Jahan Claes, Yale Department of Applied Physics

Large-scale quantum computers will require error correction in order to reliably perform computations. However, the hardware overhead for error correction remains dauntingly large, with each logical qubit potentially requiring thousands of physical qubits for reliable operation.

Wednesday, April 5, 2023 12:00 pm - 1:00 pm EDT

## IQC Student Seminar Featuring Xi Dai

### Landau-Zener tunneling: from weak to strong environment coupling

Abstract:

Landau-Zener tunneling, which describes the transitions in a two-level system during the passage through an anti-crossing, is a model applicable to a wide range of physical phenomena. Dissipation due to coupling between the system and the environment is an important factor in determining the transition rates. Using a superconducting tunable capacitively shunted flux qubit, we observe the crossover from weak to strong coupling to the environment. The weak coupling limit corresponds to small system-environment coupling and leads to environment-induced thermalization. In the strong coupling limit, environmental polarizations dress the system and transitions occur between the dressed states. Our results confirm previous theoretical studies of dissipative Landau-Zener tunneling in the weak and strong coupling limits, and motivate further work on understanding the intermediate regime. This work is relevant for understanding the role of open system effects in quantum annealing, where Landau-Zener transitions at small gaps, occurring in large scale systems, are important to understand for improving the success probability.

This talk is based on the preprint arXiv:2207.02017.

Thursday, April 6, 2023 3:00 pm - 4:00 pm EDT

## Collusion Resistant Copy-Protection for Watermarkable Functionalities

### CS/Math Seminar - Jiahui Liu (UT Austin)

Copy-protection is the task of encoding a program into a quantum state to prevent illegal duplications. A line of recent works studied copy-protection schemes under 1 -> 2 attacks'': the adversary receiving one program copy can not produce two valid copies. However, under most circumstances, vendors need to sell more than one copy of a program and still ensure that no duplicates can be generated. In this work, we initiate the study of collusion resistant copy-protection in the plain model. Our results are twofold: