Linked Questions

1 vote
1 answer
105 views

Can quantum computer perform classical computation? [duplicate]

I was going through a paper in which protocol said that the party computes modulo 'd' sum of other party secrets directly. It was not mentioned that the computation is classical. Can I assume that it ...
Chaitanya Reddy's user avatar
1 vote
1 answer
65 views

Could a quantum computer simulate any system based on different types of logic? [duplicate]

Quantum computing is based on quantum mechanics (obviously) which has different logical rules than classical/Boolean logic. However, does this mean that a quantum computer could simulate or process ...
vengaq's user avatar
  • 111
78 votes
4 answers
8k views

Can a Turing machine simulate a quantum computer?

I know that a Turing machine1 can theoretically simulate "anything", but I don't know whether it could simulate something as fundamentally different as a quantum-based computer. Are there any ...
user avatar
45 votes
2 answers
9k views

How is the oracle in Grover's search algorithm implemented?

Grover's search algorithm provides a provable quadratic speed-up for unsorted database search. The algorithm is usually expressed by the following quantum circuit: In most representations, a crucial ...
glS's user avatar
  • 24.8k
21 votes
1 answer
12k views

What is the difference between a qubit and classical bit?

As I understand it, the main difference between quantum and non-quantum computers is that quantum computers use qubits while non-quantum computers use (classical) bits. What is the difference between ...
luap42's user avatar
  • 1,047
9 votes
4 answers
5k views

Does a quantum computer have a clock signal and if yes how big is it?

I think there can't be a computer running software without having a clock signal. A fast classical computer has a clock rate between 4 to 5 GHz. If quantum computers are so much faster they must have ...
zomega's user avatar
  • 203
11 votes
4 answers
2k views

Grover's algorithm in a nutshell

I am trying to understand Grover's algorithm. I read that this algorithm is able to find an entry in an unsorted list in just $\sqrt N$ steps, and needs only $\log N$ space. I understand entanglement ...
Hubert Schölnast's user avatar
10 votes
1 answer
314 views

Are there any encryption suites which can be cracked by classical computers but not quantum computers?

Are there any encryption suites that can be cracked by usual computers or super computers, but not quantum computers? If that's possible, what assumptions will it depend on? (Factorizing big numbers, ...
MCCCS's user avatar
  • 213
3 votes
1 answer
1k views

Can a quantum computer run classical algorithms?

I realize that fundamentally speaking quantum and classical computers might as well be apples and oranges, and that for very specific problems such as integer factorization with Shor's algorithm ...
Steve Mucci's user avatar
2 votes
2 answers
692 views

Are there problems that a classical computer can solve and a quantum computer can never solve?

Apologies if this is a silly question. But I've heard quantum computers can solve problems that classical computers can't. What about the converse, are there any problems that a classical computer can ...
More Anonymous's user avatar