## What is a Turing machine used for?

A Turing machine is an abstract computational model that performs computations by reading and writing to an infinite tape. Turing machines provide a powerful computational model for solving problems in computer science and testing the limits of computation — are there problems that we simply cannot solve?

### Is there a real Turing machine?

Turing’s machine is not a real machine. It’s a mathematical model, a concept, just like state machines, automata or combinational logic. It exists purely in the abstract. (Although “real” implementations of the Turing machine do exist, like in this foundational computer science paper.)

#### Why was Turing machine invented?

1.1, Turing machines were originally intended to formalize the notion of computability in order to tackle a fundamental problem of mathematics.

**Is a Turing machine efficient?**

Turing machines can be efficiently simulated by the General Purpose Analog Computer. The Church-Turing thesis states that any sufficiently powerful computational model which captures the notion of algorithm is computationally equivalent to the Turing machine.

**Can a quantum computer simulate a Turing machine?**

Yes, a quantum computer could be simulated by a Turing machine, though this shouldn’t be taken to imply that real-world quantum computers couldn’t enjoy quantum advantage, i.e. a significant implementation advantage over real-world classical computers.

## Are quantum computers more powerful than Turing machines?

It is known that Turing machines are not so efficient, though they polynomially simulate classical computers. Quantum computers are believed to be exponentially more efficient than Turing machines. In this sense, you can beat Turing machines (if you could only build a scalable quantum computer).

### Which one is more powerful than Turing machine?

#### Is a quantum computer more powerful than a Turing machine?

**Is quantum computing Turing complete?**

The quantum computing gate model is not Turing complete. (Rea- son: quantum gates compute only total functions, functions defined everywhere.)