Niel de Beaudrap's user avatar
Niel de Beaudrap's user avatar
Niel de Beaudrap's user avatar
Niel de Beaudrap
  • Member for 5 years, 11 months
  • Last seen more than a month ago
  • Oxford, United Kingdom
32 votes
Accepted

How to derive the CNOT matrix for a 3-qubit system where the control & target qubits are not adjacent?

28 votes

What are the models of quantum computation?

27 votes
Accepted

Is there any general statement about what kinds of problems can be solved more efficiently using a quantum computer?

26 votes
Accepted

How to calculate circuit depth properly?

25 votes
Accepted

What is postselection in quantum computing?

24 votes

Why does the "Phase Kickback" mechanism work in the Quantum phase estimation algorithm?

21 votes
Accepted

Why is a quantum computer in some ways more powerful than a nondeterministic Turing machine?

20 votes

Is quantum computing just pie in the sky?

19 votes
Accepted

Why can't there be an error correcting code with fewer than 5 qubits?

19 votes
Accepted

When will we know that quantum supremacy has been reached?

19 votes
Accepted

What is the use of categorical quantum mechanics?

18 votes

What are the models of quantum computation?

17 votes
Accepted

Intuition about Knill-Laflamme QEC conditions

15 votes
Accepted

Is there a closure property for the entire Clifford hierarchy?

14 votes

How and why does swap test works?

14 votes

Is error correction necessary?

14 votes
Accepted

Why do we use the standard gate set that we do?

14 votes
Accepted

Graphical Calculus for Quantum Circuits

13 votes
Accepted

How is computation done in a 2D surface code array?

13 votes
Accepted

What is the difference between "code space", "code word" and "stabilizer code"?

13 votes

Why are quantum gates unitary and not special unitary?

12 votes
Accepted

What is the difference between a qubit and a quantum state?

12 votes

What are the models of quantum computation?

12 votes

What is the difference between superpositions and mixed states?

12 votes
Accepted

What do double wires mean in quantum circuits, and how do they relate to if statements?

12 votes

How can I build a circuit to generate an equal superposition of 3 outcomes for 2 qubits?

11 votes
Accepted

How to re-create the following circuit image?

11 votes

Advances on imperfect quantum copying

11 votes

What are the models of quantum computation?

11 votes
Accepted

Why is the Pauli group used for stabilizers?