A Converse for fault-tolerant Quantum Computation

18 February 2025

Title: A Converse for fault-tolerant Quantum Computation

Speaker: Dr. Uthirakalyani G., Graduated from Indian Institute of Technology Madras

Abstract of Talk: Quantum computers have been gaining much attention since their potential exponential speed up against their classical counterparts. Decoherence of the qubits, whilst interacting with the environment, collapses them, making them lose their quantum properties. This makes it essential to devise error correction schemes on the limited number of qubits and prevent decoherence to obtain an error-free computation from the quantum computer.

Quantum converse thresholds define the probability of error/noise in quantum computers above which an accurate computation can never be performed using the quantum computer, no matter how much the redundancy is increased. These converse bounds also translate to a lower bound on the redundancy needed for an accurate quantum computation. We focus on obtaining such converse bounds for quantum computations. Further, physical resource constraints in quantum circuits escalate noise levels when increasing redundancy, thus making numerous fault-tolerance schemes useless. So, we characterise the effect of resource constraints and derive the lower bound on redundancy for quantum circuits with classical inputs and outputs under resource-constrained noise.

Profile of Speaker: I graduated from Indian Institute of technology Madras in July 2024, with a PhD in Electrical Engineering and specialisation in Quantum Information theory. My interests include Information Networks, Quantum error correction and error mitigation.