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John Parker's user avatar
John Parker
  • Member for 3 years, 1 month
  • Last seen more than a month ago
8 votes
1 answer
2k views

What are spin-coherent states?

8 votes
1 answer
4k views

What's the role of mixer in QAOA?

8 votes
2 answers
640 views

What is the difference between amplitude amplification, amplitude estimation, and phase estimation?

7 votes
1 answer
905 views

What is the "no fast-forwarding theorem"?

6 votes
1 answer
729 views

Oblivious Amplitude Amplification & Eigenstate decomposition

5 votes
1 answer
323 views

Why does Hamiltonian simulation seek to find the energy minimum, if eigenvalues of unitaries are always unimodular?

5 votes
1 answer
301 views

What is a simple example showing the issues of not doing the "uncomputation" step?

5 votes
1 answer
434 views

Why does the bit flip channel produce a uniform contraction of $1-2p$?

5 votes
1 answer
981 views

How does the performance of QAOA and VQE compare to Grover's?

4 votes
1 answer
310 views

Variational Quantum Linear Solver (Hadamard test): circuit question

4 votes
1 answer
829 views

What is the relation between Hadamard transformation and QFT?

4 votes
1 answer
258 views

Implementing "computable phase shifts" using T Toffoli ( problem 4.1 from Nielsen and Chuang's)

3 votes
1 answer
222 views

Why are all the eigenvalues of a "Hermitian block-encoding" equal to $\pm1$?

3 votes
2 answers
201 views

Normalization question in VQLS

3 votes
1 answer
154 views

In block encoding, how to determine the dimension of the elements from $\alpha(⟨0|^{\otimes a}\otimes I)U(|0〉^{\otimes a}\otimes|\psi〉)=A|\psi〉$?

2 votes
1 answer
542 views

Wick rotation of the Schrödinger equation

2 votes
1 answer
309 views

Initial state preparation for Hadamard test

2 votes
0 answers
75 views

What's the importance of a relationship with Gibbs state in the context of VarQITE or variational algorithms?

2 votes
1 answer
173 views

In the context of block-encoding, what does $|0\rangle\otimes I$ represent?

2 votes
1 answer
131 views

Manipulating the amplitude of state based on the state information

2 votes
2 answers
373 views

How does a Hadamard discrete-time quantum walk result in a skewed distribution?

2 votes
3 answers
2k views

Why does the trace of density operators need to be one?

2 votes
1 answer
102 views

What is entanglement barrier?

1 vote
0 answers
77 views

Quantum Boltzmann Machine and Gibbs state

1 vote
1 answer
62 views

References about deriving the complexity of a given algorithm

0 votes
1 answer
157 views

Trace calculation from the basis to |+> and |-> states

0 votes
1 answer
134 views

In the amplitude amplification algorithm in Nielsen and Chuang's book, why is the error probability $M/N$?