Close

Filter courses

Level
Subcategories
Show courses Show filters
Close

Quantum Computer

01 /Quantum Computers 02 /How to build a qubit 03 /Spin qubits (beginner level) 04 /Operations on spin qubits (beginner level) 05 /Electron spin qubits 06 /Capturing a single electron 07 /Quantum dot qubits 08 /Quantum control and readout 09 /Qubit errors 10 /NV center qubits 11 /Operations on NV center qubits 12 /The Transmon Qubit - A basis for the Quantum Computer 13 /Operations on the Transmon Qubit - Circuit QED 14 /Single-qubit operations on the Transmon qubit 15 /Measurements on the Transmon Qubit 16 /Two-qubit operations on the Transmon qubit 17 /Topological qubits: Anyons 18 /Operations on anyons: Braiding 19 /Operations on anyons: Real-life experiments 20 /Topological quantum computing: Majorana fermions and where to find them 21 /Majorana bound states in superconductors 22 /How do you measure Majorana bound states? 23 /A framework for the future Quantum Computer 24 /The Building Blocks of a Quantum Computer 25 /How to build a Quantum Algorithm - Quantum Circuits 26 /How do you program a quantum algorithm? 27 /The compiler of a quantum computer 28 /Micro-architectures 29 /How do we connect our quantum system to a classical interface? 30 /Assembling a Quantum Processor 31 /Microwave drivers for qubits 32 /Implementation of microwave drivers 33 /Quantum error correction 34 /Surface codes 35 /Fault-tolerant Quantum Error Correction with surface codes

Fault-tolerant Quantum Error Correction with surface codes

To ensure that our quantum bits remain protected, we have to perform error-detecting and correcting measurements very frequently. However, these error-correcting circuits themselves are also prone to errors, which can cause the efficiency of the algorithm to go down eventually. That’s not what we want!

Designing circuits which perform fault-tolerant quantum error correction is a cutting-edge field of research. In this video, we will discuss one of the most promising candidate-algorithms that does just this: surface codes. Professor Barbara Terhal concludes with the introduction of the fault-tolerant threshold, the physical error rate which must be reached for quantum error correction to be effective. 

Prerequisite knowledge

Further thinking

Stabilizer codes perform parity checks in order to detect errors. We have seen a general idea of how to detect X and Z errors. Based on this idea, how would you detect a Y-type  error?

Solution

Further reading

A bit philosophical, but still interesting is this paper by prof. Barbara Terhal herself, addressing the question of whether there is a fundamental reason why quantum information is more fragile than classical information.

This paper was written by A. Fowler et al. as an introduction to surface codes.

Here is a paper by M.H. Devoret and R. Schoelkopf, describing the different stages to reach before achieving fault-tolerant quantum computation.