(completely theoretical and unfinished)
|ψ₁⟩ ⊗ |ψ₂⟩ ⊗ |ψ₃⟩ ⊗ |ψ₄⟩ = (α₁|00⟩ + β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩) ⊗ (α₂|00⟩ + β₂|01⟩ + γ₂|10⟩ + δ₂|11⟩) ⊗ (α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩) ⊗ (α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩)
---------------------------------------------------------------------------
|ϕ⟩ = α|0⟩ + β|1⟩
|ψ⟩ = γ|0⟩ + δ|1⟩
|ξ⟩ = ε|0⟩ + ζ|1⟩
|η⟩ = η|0⟩ + θ|1⟩
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩) ⊗ (α₂|00⟩ + β₂|01⟩ + γ₂|10⟩ + δ₂|11⟩) ⊗ (α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩) ⊗ (α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩)
|ϕ⟩ = α|00⟩ + β|01⟩ + γ|10⟩ + δ|11⟩
α|+⟩ + β|-⟩ + γ|+⟩ + δ|-⟩
α|-⟩ + β|+⟩ + γ|-⟩ + δ|+⟩
α|-⟩ + β|-⟩ + γ|+⟩ + δ|+⟩
α|+⟩ + β|+⟩ + γ|-⟩ + δ|-⟩
|ψ⟩ = α'|00⟩ + β'|01⟩ + γ'|10⟩ + δ'|11⟩
α'|+⟩ + β'|-⟩ + γ'|+⟩ + δ'|-⟩
α'|-⟩ + β'|+⟩ + γ'|-⟩ + δ'|+⟩
α'|-⟩ + β'|-⟩ + γ'|+⟩ + δ'|+⟩
α'|+⟩ + β'|+⟩ + γ'|-⟩ + δ'|-⟩
|ξ⟩ = α''|00⟩ + β''|01⟩ + γ''|10⟩ + δ''|11⟩
α''|+⟩ + β''|-⟩ + γ''|+⟩ + δ''|-⟩
α''|-⟩ + β''|+⟩ + γ''|-⟩ + δ''|+⟩
α''|-⟩ - β''|-⟩ + γ''|+⟩ + δ''|+⟩
α''|+⟩ + β''|+⟩ + γ''|-⟩ + δ''|-⟩
|η⟩ = α'''|00⟩ + β'''|01⟩ + γ'''|10⟩ + δ'''|11⟩
α'''|+⟩ + β'''|-⟩ + γ'''|+⟩ + δ'''|-⟩
α'''|-⟩ + β'''|+⟩ + γ'''|-⟩ + δ'''|+⟩
α'''|-⟩ + β'''|-⟩ + γ'''|+⟩ + δ'''|+⟩
α'''|+⟩ + β'''|+⟩ + γ'''|-⟩ + δ'''|-⟩
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩
α|+⟩ + β|-⟩ + γ|+⟩ + δ|-⟩ )
⊗
(α₂|00⟩ + β₂|01⟩ + γ₂|10⟩ + δ₂|11⟩
α'|+⟩ + β'|-⟩ + γ'|+⟩ + δ'|-⟩ )
⊗
(α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩
α'|+⟩ + β'|-⟩ + γ'|+⟩ + δ'|-⟩ )
⊗
(α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩
α'''|+⟩ + β'''|-⟩ + γ'''|+⟩ + δ'''|-⟩ )
set 1:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩) ⊗ (α₂|00⟩ + β₂|01⟩ + γ₂|10⟩ + δ₂|11⟩) ⊗ (α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩) ⊗ (α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩)
= α₁α₂α₃α₄|0000⟩ + α₁α₂α₃β₄|0001⟩ + α₁α₂α₃γ₄|0010⟩ + α₁α₂α₃δ₄|0011⟩ + α₁α₂β₃α₄|0100⟩ + α₁α₂β₃β₄|0101⟩ + α₁α₂β₃γ₄|0110⟩ + α₁α₂β₃δ₄|0111⟩ + α₁α₂γ₃α₄|1000⟩ + α₁α₂γ₃β₄|1001⟩ + α₁α₂γ₃γ₄|1010⟩ + α₁α₂γ₃δ₄|1011⟩ + α₁α₂δ₃α₄|1100⟩ + α₁α₂δ₃β₄|1101⟩ + α₁α₂δ₃γ₄|1110⟩ + α₁α₂δ₃δ₄|1111⟩ + ... + β₁β₂β₃δ₄|1101⟩ + β₁β₂γ₃α₄|1010⟩ + β₁β₂γ₃β₄|1011⟩ + β₁β₂γ₃γ₄|1100⟩ + β₁β₂γ₃δ₄|1101⟩ + β₁β₂δ₃α₄|1110⟩ + + β₁β₂δ₃α₄|1111⟩
Set 2:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁-|00⟩ + β₁-|01⟩ + γ₁-|10⟩ + δ₁-|11⟩) ⊗ (α₂-|00⟩ + β₂-|01⟩ + γ₂-|10⟩ + δ₂-|11⟩) ⊗ (α₃-|00⟩ + β₃-|01⟩ + γ₃-|10⟩ + δ₃-|11⟩) ⊗ (α₄-|00⟩ + β₄-|01⟩ + γ₄-|10⟩ + δ₄-|11⟩)
= α₁α₂α₃α₄-|0000⟩ + α₁α₂α₃β₄-|0001⟩ + α₁α₂α₃γ₄-|0010⟩ + α₁α₂α₃δ₄-|0011⟩ + α₁α₂β₃α₄-|0100⟩ + α₁α₂β₃β₄-|0101⟩ + α₁α₂β₃γ₄-|0110⟩ + α₁α₂β₃δ₄-|0111⟩ + α₁α₂γ₃α₄-|1000⟩ + α₁α₂γ₃β₄-|1001⟩ + α₁α₂γ₃γ₄-|1010⟩ + α₁α₂γ₃δ₄-|1011⟩ + α₁α₂δ₃α₄-|1100⟩ + α₁α₂δ₃β₄-|1101⟩ + α₁α₂δ₃γ₄-|1110⟩ + α₁α₂δ₃δ₄-|1111⟩ + ... + β₁β₂β₃δ₄-|1101⟩ + β₁β₂γ₃α₄-|1010⟩ + β₁β₂γ₃β₄-|1011⟩ + β₁β₂γ₃γ₄-|1100⟩ + β₁β₂γ₃δ₄-|1101⟩ + β₁β₂δ₃α₄-|1110⟩ +... + β₁β₂δ₃α₄-|1111⟩
= α₁α₂α₃α₄|0000⟩
+
α₁α₂α₃β₄-|0001⟩
+
α₁α₂α₃γ₄|0010⟩
+
α₁α₂α₃δ₄-|0011⟩
+
α₁α₂β₃α₄|0100⟩
+
α₁α₂β₃β₄-|0101⟩
+
α₁α₂β₃γ₄|0110⟩
+
α₁α₂β₃δ₄-|0111⟩
+
α₁α₂γ₃α₄|1000⟩
+
α₁α₂γ₃β₄-|1001⟩
+
α₁α₂γ₃γ₄|1010⟩
+
α₁α₂γ₃δ₄-|1011⟩
+
α₁α₂δ₃α₄|1100⟩
+
α₁α₂δ₃β₄-|1101⟩
+
α₁α₂δ₃γ₄|1110⟩
+
α₁α₂δ₃δ₄-|1111⟩
+ ... +
β₁β₂β₃δ₄|1101⟩
+
β₁β₂γ₃α₄-|1010⟩
+
β₁β₂γ₃β₄|1011⟩
+
β₁β₂γ₃γ₄-|1100⟩
+
β₁β₂γ₃δ₄|1101⟩
+
β₁β₂δ₃α₄-|1110⟩
+... +
β₁β₂δ₃α₄|1111⟩
------------------------------------------------------------------
define the phase shift gate S as the following unitary matrix:
S = [1, 0; 0, i]
1:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩) ⊗ (α₂|00⟩ + β₂|01⟩ + γ₂|10⟩ + δ₂|11⟩) ⊗ (α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩) ⊗ (α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩)
Step 1: Apply the phase shift gate S to the qubit in the state |01⟩
After applying the phase shift gate, the equation becomes:
1': |ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + i*β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩) ⊗ (α₂|00⟩ + β₂|01⟩ + γ₂|10⟩ + δ₂|11⟩) ⊗ (α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩) ⊗ (α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩)
2:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁-|00⟩ + β₁-|01⟩ + γ₁-|10⟩ + δ₁-|11⟩) ⊗ (α₂-|00⟩ + β₂-|01⟩ + γ₂-|10⟩ + δ₂-|11⟩) ⊗ (α₃-|00⟩ + β₃-|01⟩ + γ₃-|10⟩ + δ₃-|11⟩) ⊗ (α₄-|00⟩ + β₄-|01⟩ + γ₄-|10⟩ + δ₄-|11⟩)
After applying the phase shift gate, the equation becomes:
2': |ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁-|00⟩ + e^(iπ/2)β₁-|01⟩ + γ₁-|10⟩ + δ₁-|11⟩) ⊗ (α₂-|00⟩ + β₂-|01⟩ + γ₂-|10⟩ + δ₂-|11⟩) ⊗ (α₃-|00⟩ + β₃-|01⟩ + γ₃-|10⟩ + δ₃-|11⟩) ⊗ (α₄-|00⟩ + β₄-|01⟩ + γ₄-|10⟩ + δ₄-|11⟩)
3:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + β₁-|01⟩ + γ₁|10⟩ + δ₁-|11⟩) ⊗ (α₂|00⟩ + β₂-|01⟩ + γ₂|10⟩ + δ₂-|11⟩) ⊗ (α₃|00⟩ + β₃-|01⟩ + γ₃|10⟩ + δ₃-|11⟩) ⊗ (α₄|00⟩ + β₄-|01⟩ + γ₄-|10⟩ + δ₄|11⟩)
After applying the phase shift gate, the equation becomes:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + e^(iπ/2)β₁-|01⟩ + γ₁|10⟩ + e^(iπ/2)δ₁-|11⟩) ⊗ (α₂|00⟩ + e^(iπ/2)β₂-|01⟩ + γ₂|10⟩ + e^(iπ/2)δ₂-|11⟩) ⊗ (α₃|00⟩ + e^(iπ/2)β₃-|01⟩ + γ₃|10⟩ + e^(iπ/2)δ₃-|11⟩) ⊗ (α₄|00⟩ + e^(iπ/2)β₄-|01⟩ + γ₄|10⟩ + δ₄|11⟩)
4:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁-|00⟩ + β₁|01⟩ + γ₁-|10⟩ + δ₁|11⟩) ⊗ (α₂-|00⟩ + β₂|01⟩ + γ₂-|10⟩ + δ₂|11⟩) ⊗ (α₃-|00⟩ + β₃|01⟩ + γ₃-|10⟩ + δ₃|11⟩) ⊗ (α₄-|00⟩ + β₄|01⟩ + γ₄-|10⟩ + δ₄|11⟩)
After applying the phase shift gate, the equation becomes:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩' = (e^(iθ)α₁-|00⟩ + e^(iθ)β₁|01⟩ + e^(iθ)γ₁-|10⟩ + e^(iθ)δ₁|11⟩) ⊗ (e^(iθ)α₂-|00⟩ + e^(iθ)β₂|01⟩ + e^(iθ)γ₂-|10⟩ + e^(iθ)δ₂|11⟩) ⊗ (e^(iθ)α₃-|00⟩ + e^(iθ)β₃|01⟩ + e^(iθ)γ₃-|10⟩ + e^(iθ)δ₃|11⟩) ⊗ (e^(iθ)α₄-|00⟩ + e^(iθ)β₄|01⟩ + e^(iθ)γ₄-|10⟩ + e^(iθ)δ₄|11⟩)
---------------------------------------------------------------------
Here, i is the imaginary unit and θ is the phase shift angle. The prime notation denotes the state after the phase shift gate operation.
----------------------------------------------------------------------
let's say we have these four quantum states:
|ϕ⟩ = α|0⟩ + β|1⟩
|ψ⟩ = γ|0⟩ + δ|1⟩
|ξ⟩ = ε|0⟩ + ζ|1⟩
|η⟩ = η|0⟩ + θ|1⟩
We can represent these states in the computational basis as:
|ϕ⟩ = α|00⟩ + β|01⟩
|ψ⟩ = γ|10⟩ + δ|11⟩
|ξ⟩ = ε|00⟩ + ζ|01⟩
|η⟩ = η|10⟩ + θ|11⟩
The tensor product of these states in the computational basis would be:
|ϕ⟩ ⊗ |ψ⟩ ⊗ |ξ⟩ ⊗ |η⟩ = (α|00⟩ + β|01⟩) ⊗ (γ|10⟩ + δ|11⟩) ⊗ (ε|00⟩ + ζ|01⟩) ⊗ (η|10⟩ + θ|11⟩) = αγεη|0000⟩ + αγζθ|0001⟩ + βγ
In the computational basis, we can express these states as:
|ϕ⟩ = α|00⟩ + β|01⟩ + γ|10⟩ + δ|11⟩
|ψ⟩ = α'|00⟩ + β'|01⟩ + γ'|10⟩ + δ'|11⟩
|ξ⟩ = α''|00⟩ + β''|01⟩ + γ''|10⟩ + δ''|11⟩
|η⟩ = α'''|00⟩ + β'''|01⟩ + γ'''|10⟩ + δ'''|11⟩
In the Hadamard basis, we can express these states as:
|ϕ⟩ = α|+⟩ + β|-⟩
|ψ⟩ = α'|+⟩ + β'|-⟩
|ξ⟩ = α''|+⟩ + β''|-⟩
|η⟩ = α'''|+⟩ + β'''|-⟩
--------------------------------------------------------------------
1': |ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + i*β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩) ⊗ (α₂|00⟩ + β₂|01⟩ + γ₂|10⟩ + δ₂|11⟩) ⊗ (α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩) ⊗ (α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩) / sqrt(4)
2': |ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁-|00⟩ + e^(iπ/2)β₁-|01⟩ + γ₁-|10⟩ + δ₁-|11⟩) ⊗ (α₂-|00⟩ + β₂-|01⟩ + γ₂-|10⟩ + δ₂-|11⟩) ⊗ (α₃-|00⟩ + β₃-|01⟩ + γ₃-|10⟩ + δ₃-|11⟩) ⊗ (α₄-|00⟩ + β₄-|01⟩ + γ₄-|10⟩ + δ₄-|11⟩) / sqrt(4)
3':|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + e^(iπ/2)β₁-|01⟩ + γ₁|10⟩ + e^(iπ/2)δ₁-|11⟩) ⊗ (α₂|00⟩ + e^(iπ/2)β₂-|01⟩ + γ₂|10⟩ + e^(iπ/2)δ₂-|11⟩) ⊗ (α₃|00⟩ + e^(iπ/2)β₃-|01⟩ + γ₃|10⟩ + e^(iπ/2)δ₃-|11⟩) ⊗ (α₄|00⟩ + e^(iπ/2)β₄-|01⟩ + γ₄|10⟩ + δ₄|11⟩) / sqrt(4)
4':|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩' = (e^(iθ)α₁-|00⟩ + e^(iθ)β₁|01⟩ + e^(iθ)γ₁-|10⟩ + e^(iθ)δ₁|11⟩) ⊗ (e^(iθ)α₂-|00⟩ + e^(iθ)β₂|01⟩ + e^(iθ)γ₂-|10⟩ + e^(iθ)δ₂|11⟩) ⊗ (e^(iθ)α₃-|00⟩ + e^(iθ)β₃|01⟩ + e^(iθ)γ₃-|10⟩ + e^(iθ)δ₃|11⟩) ⊗ (e^(iθ)α₄-|00⟩ + e^(iθ)β₄|01⟩ + e^(iθ)γ₄-|10⟩ + e^(iθ)δ₄|11⟩) / sqrt(4)
Well there was an S gate and CNOT gate - however, I suppose you wouldn't know that from just this equation alone. Are there any specific observables associated?
What is the overall state of the system described by the expression?
What operations or gates have been applied to the qubits? Identify any/all specific gates or transformations mentioned in the expression.
What are the meanings and interpretations of the variables and terms in the expression -- what do α, β, γ, and δ represent? What do the subscripts 1, 2, 3, and 4 indicate?
How many qubits are involved in the expression? Identify the individual qubits and their corresponding states, please.
nostr:npub1tsgw6pncspg4d5u778hk63s3pls70evs4czfsmx0fzap9xwt203qtkhtk4 nostr:npub13wfgha67mdxall3gqp2hlln7tc4s03w4zqhe05v4t7fptpvnsgqs0z4fun
Can you explain this:
|ϕ₁⟩ ⊗ |ψ₂⟩ ⊗ |ξ₃⟩ ⊗ |η₄⟩ = (α₁|00⟩ + β₁|01⟩ + γ₁|10⟩ + δ₁|11⟩) ⊗ (α₂|00⟩ + β₂⊕|01⟩ + γ₂⊕|10⟩ + δ₂|11⟩) ⊗ (α₃|00⟩ + β₃|01⟩ + γ₃|10⟩ + δ₃|11⟩) ⊗ (α₄|00⟩ + β₄|01⟩ + γ₄|10⟩ + δ₄|11⟩)/√π
Another french song s'il te plaît