What is the role of linear operators in quantum mechanics?

In summary, the speaker is a university student seeking help with linear operators in quantum mechanics. They provide two equations (Ô1 and Ô2) and ask for help in finding new functions obtained by acting with these operators on two given functions (g(x,t) and h(x,t)). The student initially struggles with finding the second function but later realizes their mistake.
  • #1
Roodles01
128
0

Homework Statement


Just starting third level Uni. stuff & am faced with linear operators from Quantum Mechanics & need a little help.
OK, an operator, Ô, is said to be linear if it satisfies the equation
Ô(α f1 + β f2) = α(Ô f1) + β(Ô f2)
Fine

but I have an equation I can't wrap my head around, maybe just rusty, a hint would be nice, though.



Homework Equations


Ô1 = d/dx;
Ô2 =3 d/dx +3x^2;

 
Find the new functions obtained by acting with each of these operators on
(a) g(x, t) =3 d/dx +3x^2
(b) h(x, t)=α sin(kx − ωt).



The Attempt at a Solution


Now
Ô1 g(x,t) = 6xt^3
But not sure about how to get
Ô2 g(x,t) =

how to get this middle bit, please . . . . .

Answer is 18xt^3 + 9x^4 t^3
 
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  • #2
You realize there's no 't' dependence in g(x,t), so that the outcome must be independent of t, right ? Actually the way you wrote it, g(x,t) is Ô2, not a wavefunction, but also an operator.
 
  • #3
I went back to the question, scanned the problem in & looking again showed a huge error in seeing things.
What a twit.
 

Related to What is the role of linear operators in quantum mechanics?

1. What is a quantum linear operator?

A quantum linear operator is a mathematical representation of an observable quantity in quantum mechanics. It is a linear transformation that acts on a quantum state to produce a new quantum state.

2. How are quantum linear operators different from classical linear operators?

Quantum linear operators differ from classical linear operators in that they operate on quantum states, which are described by a wave function, rather than classical states which are described by a set of physical variables. In addition, quantum linear operators must obey the rules of quantum mechanics, such as the superposition principle and the uncertainty principle.

3. What are the key properties of quantum linear operators?

The key properties of quantum linear operators include linearity, unitarity, and hermiticity. Linearity means that the operator behaves in a predictable way when applied to a superposition of quantum states. Unitarity ensures that the operator preserves the overall probability of the quantum state. Hermiticity means that the operator is self-adjoint, allowing for the calculation of expectation values.

4. How are quantum linear operators used in quantum computing?

In quantum computing, quantum linear operators are used to represent quantum gates, which are the basic building blocks of quantum circuits. These operators act on quantum bits (qubits) to perform calculations and operations. By manipulating the quantum linear operators, quantum algorithms can be implemented to solve certain problems more efficiently than classical computers.

5. What are some examples of commonly used quantum linear operators?

Some commonly used quantum linear operators include the Pauli matrices, which represent spin states in quantum systems, the identity operator, which leaves a quantum state unchanged, and the Hadamard gate, which is used in quantum algorithms for creating superposition states. Other examples include the phase shift and controlled-NOT (CNOT) operators.

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