PragProg Customers

Quantum Computing: Wrong X gate in circuit for AH2 and |q1> (page 309)

zoufala

zoufala

Quantum Computing: Wrong X gate in circuit for AH2 and |q1> (page 309)

@nihal.mehta

I’m just starting with quantum computing, therefore I’m not completely sure. But for me the bottom-left X gate in the circuit diagram looks wrong, I think it should be an H gate?

1 comment
#errata/book-quantum-computing
0 516 1

First Post!

nihal.mehta

nihal.mehta

Author of Quantum Computing

Hello,
Yes you are correct. The bottom gate in the left AH2 block should be an H gate, not X as shown. The figure is incorrect.
The matrix equation at the bottom of the page is also incorrect. Specifically, the matrix on the right of the 5 matrix multiplication should be replaced with the matrix on the left. The result though is correct.
Thanks for pointing this out.
Best,
Nihal

Post #2

Where Next?

View thread on forum
View Quantum Computing's book portal
Post errata for this book
Post a suggestion for this book
Post a question about this book
Post a review about this book
Home PragProg Customers
#errata/book-quantum-computing
0 516 1
Last post

Popular Pragmatic Bookshelf topics Top

ianwillie
PragProg Customers

Build Websites with Hugo: Code will not run in a working Hugo setup
Hello Brian, I have some problems with running the code in your book. I like the style of the book very much and I have learnt a lot as...
#question/book-build-websites-with-hugo
0 1501 3
New
yulkin
PragProg Customers

Programming Flutter: Image.toByteData() does not exist (page40)
your book suggests to use Image.toByteData() to convert image to bytes, however I get the following error: "the getter ‘toByteData’ isn’t...
/book-programming-flutter#question
1 4102 2
New
simonpeter
PragProg Customers

Web Development with Clojure, Third Edition: (create-migration "guestbook") not working (page 9)
When I try the command to create a pair of migration files I get an error. user=> (create-migration "guestbook") Execution error (Ill...
#errata/book-web-development-with-clojure-third-edition
5 1788 4
New
raul
PragProg Customers

Distributed Services with Go: Chapter 1 Suggestions
Hi Travis! Thank you for the cool book! :slight_smile: I made a list of issues and thought I could post them chapter by chapter. I’m rev...
#errata/book-distributed-services-with-go
2 1185 3
New
adamwoolhether
PragProg Customers

Distributed Services with Go: receiving Unknown flag: --go_opt when compiling protobuf (page 20)
When trying to generate the protobuf .go file, I receive this error: Unknown flag: --go_opt libprotoc 3.12.3 MacOS 11.3.1 Googling ...
/book-distributed-services-with-go
0 4924 3
New
patoncrispy
PragProg Customers

Hands-on Rust: Adequate docs for bracket_lib
I’m new to Rust and am using this book to learn more as well as to feed my interest in game dev. I’ve just finished the flappy dragon exa...
#question/book-hands-on-rust
5 1516 3
New
adamwoolhether
PragProg Customers

Distributed Services With Go: Unable to pass readiness/liveness checks. (page 210, 215)
I’m not quite sure what’s going on here, but I’m unable to have to containers successfully complete the Readiness/Liveness checks. I’m im...
/book-distributed-services-with-go
5 1420 5
New
Charles
PragProg Customers

Programming Phoenix LiveView: book not updated to version 1.6 (p. 18)
In general, the book isn’t yet updated for Phoenix version 1.6. On page 18 of the book, the authors indicate that an auto generated of ro...
#errata/book-programming-phoenix-liveview
9 2051 12
New
dsmith42
PragProg Customers

iOS Unit Testing by Example: 54 Don't seem to be getting the print out on tests (Xcode 13.2)
Hey there, I’m enjoying this book and have learned a few things alredayd. However, in Chapter 4 I believe we are meant to see the “>...
#question/book-ios-unit-testing-by-example
0 1963 3
New
dachristenson
PragProg Customers

Kotlin and Android Development featuring Jetpack: End Ch. 11 app runs but consistently crashes
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
#question/book-kotlin-and-android-development-featuring-jetpack
0 936 8
New

Other popular topics Top

PragmaticBookshelf
Game Dev>Learning Resources

The Ray Tracer Challenge
Brace yourself for a fun challenge: build a photorealistic 3D renderer from scratch! In just a couple of weeks, build a ray tracer that r...
pragprog.com
#pragprog#published-book/book-the-ray-tracer-challenge#algorithms
3 6115 0
New
DevotionGeo
Backend>Chat

What is the reason behind Rust’s web framework, Rocket, not performing as well as expected in the Techempower benchmarks?
I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
#web-frameworks/rust
36 7463 11
New
PragmaticBookshelf
Backend>Learning Resources

Concurrent Data Processing in Elixir
Learn different ways of writing concurrent code in Elixir and increase your application's performance, without sacrificing scalability or...
pragprog.com
#pragprog/elixir#published-book/book-concurrent-data-processing-in-elixir
78 6059 24
New
Margaret
General Dev>Dev Chat

PragProg’s Medium Posts
Hello everyone! This thread is to tell you about what authors from The Pragmatic Bookshelf are writing on Medium.
#pragprog#blog-post
1147 29994 760
New
Maartz
General Dev>Dev Chat

Roc Language - a new purely functional programming language built for speed and ergonomics
Hi folks, I don’t know if I saw this here but, here’s a new programming language, called Roc Reminds me a bit of Elm and thus Haskell. ...
#programminguages#functional-programming
49 5164 14
New
PragmaticBookshelf
Community>In The Spotlight

Spotlight: VM Brasseur (Author) Interview and AMA!
Author Spotlight: VM Brasseur @vmbrasseur We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...
#author-spotlight/book-forge-your-future-with-open-source
16 5051 11
New
First poster: bot
General Dev>In The News

Zig now has built-in HTTP server and client in std
zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig. General-purpose programming language and toolchain for maintaini...
github.com
/zig#http
0 5624 0
New
AstonJ
Backend>Questions

Psql: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: No such file or directory
If you’re getting errors like this: psql: error: connection to server on socket “/tmp/.s.PGSQL.5432” failed: No such file or directory ...
#macos/rails/postgresql
1 5553 1
New
PragmaticBookshelf
Backend>Learning Resources

Agile Web Development with Rails 8
Get the comprehensive, insider information you need for Rails 8 with the new edition of this award-winning classic. Sam Ruby @rubys ...
pragprog.com
#pragprog#web-development/ruby/rails#published-book/book-agile-web-development-with-rails-8
12 7404 7
New
CommunityNews
Game Dev>In The News

Grand Theft Auto: Vice City | DOS games in browser
Open-source implementation of the classic GTA engine now running directly in your browser. Experience the reVC technology demo on DOS.Zon...
dos.zone
#games#browser
0 173 0
New
Back to top

Latest in Quantum Computing

Quantum Computing Portal ❯

PragProg Customers

Pragmatic Bookshelf PragProg Customers ❯

Latest on Devtalk

Devtalk ❯

We ❤️ helpful members!

We reward our most helpful members via our MOTM scheme - by giving away a whopping 25 books per year!

Member of the Month

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

Categories:

Sub Categories:

Popular Portals

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap