<p>This is a nice survey. It is one of the most up to date papers that you'll find about building quantum computers.</p>

<p><a href="http://www.nature.com/nature/journal/v464/n7285/full/nature08812.html" rel="noreferrer">Quantum Computers. Nature 464</a></p>

CC BY-SA 2.5
2010-08-16T22:20:10.130Z
2010-08-16T22:20:10.130Z
Marcos Villagra
<p>For actual physical implementation of conceptual quantum computing devices and what methods may be best suited for these practices, Nielsen and Chuang's book has an entire chapter which is very well written and easy to understand on this.</p>

CC BY-SA 3.0
2012-10-15T04:01:56.860Z
spelling is still wrong :)
Alessandro Cosentino
CC BY-SA 3.0
2012-10-15T04:11:26.337Z
Haha, ah the side effects of too little caffeine. Fixed both problems. Sorry about that!
Vincent Russo
CC BY-SA 2.5
2010-09-06T09:21:44.047Z
Unfortunately that chapter is now somewhat out of date, as there have been significant developments since the book was written.
Joe Fitzsimons
CC BY-SA 2.5
2010-10-20T01:14:03.480Z
The first author is Nielsen.
Tsuyoshi Ito
CC BY-SA 3.0
2010-09-05T03:39:00.097Z
2012-10-15T04:09:38.397Z
2012-10-15T04:09:38.397Z
Vincent Russo
<p>At this stage progress on experimental quantum computing is relatively slow, but there are now a wide variety of systems that can be used to implement one or more qubits. </p>

<p>At the moment the most developed systems as</p>

<ol>
<li>Ion traps</li>
<li>Liquid state NMR</li>
<li>Linear optics quantum computing</li>
<li>Superconducting qubits</li>
</ol>

<p>There has also been a lot of recent work with defects in solid state, solid state NMR, endohedral fullerenes, neutral atom traps, atom chips, etc.</p>

<p>The highest numbers of qubits tend to be in ion traps and NMR, though linear optics is doing well too. </p>

<p>As regards significant experiments, that really depends what constitutes progress to you. There was a very nice experiment back in 2007 where two separate ion traps were coupled optically, and some nice recent work on segmented ion traps, which demonstrate ways of scaling ion trap computation beyond 10 or so qubits. There has also been some very nice implementations of measurement based computation using optics, which is also important for scalability. If you have a better idea of the type of experiments you have in mind it would make the task of answering much easier.</p>

<p>The US quantum computing roadmap, available <a href="http://qist.lanl.gov/qcomp_map.shtml">here</a>, provides an excellent, though slightly dated overview of the state of the art circa 2004.</p>

CC BY-SA 3.0
2012-10-15T17:02:56.653Z
"At this stage progress on experimental quantum computing is relatively slow". Really? Apparently there is even a Quantum Moore's Law at work! ;-) http://www.quantenblog.net/physics/moores-law-quantum-computer
Martin Schwarz
CC BY-SA 3.0
2012-10-16T13:43:34.703Z
@MartinSchwarz: I think it is basically the fact that exponential growth looks linear starting off. But, I wrote that answer over two years ago, and I think it is really speeding up. I'm particularly excited about IBM's recent results.
Joe Fitzsimons
CC BY-SA 2.5
2010-08-17T03:34:29.830Z
2010-08-17T03:34:29.830Z
Joe Fitzsimons
<p><a href="http://en.wikipedia.org/wiki/Quantum_computer" rel="nofollow">Quantum Computation</a> is an active area of research that aims to take advantage of quantum physics (e.g. quantum entanglement) to advance the efficiency capabilities of computers (does not alter the <a href="http://en.wikipedia.org/wiki/Church%E2%80%93Turing_thesis" rel="nofollow">Church-Turing thesis</a>).  </p>

<p>What are the most significant experiments that have been conducted to demonstrate quantum-computing theory (such as qubits and teleportation)?</p>

CC BY-SA 2.5
2010-08-16T21:09:20.137Z
I read the question title and thought it was very vague. But the question itself is quite specific. Maybe you could edit the title to something like 'Are there known actual implementations for basic quantum computing constructs' ?
Suresh Venkat
CC BY-SA 2.5
2010-08-16T21:22:57.017Z
@Suresh: I made the change.
Shane
<reference-request><quantum-computing>
Are there any known implementations for quantum computing constructs?
Shane
# Are there any known implementations for quantum computing constructs?

(Asked by: username_0 on 2010-08-16)

[Quantum Computation](http://en.wikipedia.org/wiki/Quantum_computer) is an active area of research that aims to take advantage of quantum physics (e.g. quantum entanglement) to advance the efficiency capabilities of computers (does not alter the [Church-Turing thesis](http://en.wikipedia.org/wiki/Church%E2%80%93Turing_thesis)).

What are the most significant experiments that have been conducted to demonstrate quantum-computing theory (such as qubits and teleportation)?

**Tags:** reference-request, quantum-computing

> **Comments:**
> **username_1**: I read the question title and thought it was very vague. But the question itself is quite specific. Maybe you could edit the title to something like 'Are there known actual implementations for basic quantum computing constructs' ?  
> **username_0**: @Suresh: I made the change.  

---

## 3 answers

### Answer by username_5 on 2010-08-17. Score: 18 | Accepted answer

At this stage progress on experimental quantum computing is relatively slow, but there are now a wide variety of systems that can be used to implement one or more qubits.

At the moment the most developed systems as

1. Ion traps
2. Liquid state NMR
3. Linear optics quantum computing
4. Superconducting qubits

There has also been a lot of recent work with defects in solid state, solid state NMR, endohedral fullerenes, neutral atom traps, atom chips, etc.

The highest numbers of qubits tend to be in ion traps and NMR, though linear optics is doing well too.

As regards significant experiments, that really depends what constitutes progress to you. There was a very nice experiment back in 2007 where two separate ion traps were coupled optically, and some nice recent work on segmented ion traps, which demonstrate ways of scaling ion trap computation beyond 10 or so qubits. There has also been some very nice implementations of measurement based computation using optics, which is also important for scalability. If you have a better idea of the type of experiments you have in mind it would make the task of answering much easier.

The US quantum computing roadmap, available [here](http://qist.lanl.gov/qcomp_map.shtml), provides an excellent, though slightly dated overview of the state of the art circa 2004.

> **Comments:**
> **username_7**: "At this stage progress on experimental quantum computing is relatively slow". Really? Apparently there is even a Quantum Moore's Law at work! ;-) http://www.quantenblog.net/physics/moores-law-quantum-computer  
> **username_5**: @MartinSchwarz: I think it is basically the fact that exponential growth looks linear starting off. But, I wrote that answer over two years ago, and I think it is really speeding up. I'm particularly excited about IBM's recent results.  

---

### Answer by username_2 on 2010-08-16. Score: 15

This is a nice survey. It is one of the most up to date papers that you'll find about building quantum computers.

[Quantum Computers. Nature 464](http://www.nature.com/nature/journal/v464/n7285/full/nature08812.html)


---

### Answer by username_3 on 2010-09-05. Score: 1

For actual physical implementation of conceptual quantum computing devices and what methods may be best suited for these practices, Nielsen and Chuang's book has an entire chapter which is very well written and easy to understand on this.

> **Comments:**
> **username_5**: Unfortunately that chapter is now somewhat out of date, as there have been significant developments since the book was written.  
> **username_6**: The first author is Nielsen.  
> **username_4**: spelling is still wrong :)  
> **username_3**: Haha, ah the side effects of too little caffeine. Fixed both problems. Sorry about that!  

---

