34
votes
How does the recent Chinese quantum supremacy claim compare with Google's?
"how honest is the Chinese claim of quantum supremacy?"
It's equally (or at least as) honest in comparison to Google's claim.
In a comment to this answer at Quantum Computing Stack Exchange,...
19
votes
How can quantum computing accelerate materials modeling?
Quantum computers provide the possibility of simulating systems that are so mathematically complex that classical computers cannot practically be used. The difficulty comes from the fact that the ...
- 1,483
15
votes
How can quantum computing accelerate materials modeling?
Quantum computing has been extensively discussed as long as the first quantum computers have become a reality. As already pointed out, we are still at very early stages of such development. What we ...
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15
votes
How are quantum computers being used in drug design?
How are quantum computers being used in drug design?
They are not.
Because useful quantum computers do not exist yet.
Ask again in a couple decades :)
13
votes
How can quantum computing accelerate materials modeling?
Quantum computers potentially could provide a far more efficient way to solve the electronic structure problem: finding the ground state energy (or other properties) of electrons in a compound.
The ...
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10
votes
Accepted
Molecular orbitals and active space
As you said above, nitrogen has 2 s orbitals and one p orbital. However, one would typically freeze the chemically inactive 1s orbital, leaving you 5 electrons in 4 orbitals per atom, or 10 electrons ...
- 20k
9
votes
Accepted
What class of materials are closest to realizing the tunable coupling Hamiltonian?
Realizing this Hamiltonian in a natural material
I cannot imagine a material in which all nearest-neighbor spin-spin interactions can be adjusted arbitrarily at the same time. Spin-spin couplings ...
7
votes
Have quantum computers been proven to speed up any matter modeling algorithm?
FCI (Full Configuration Interaction)
The FCI expansion of a wavefunction allows us to obtain the exact energy of a system given a basis set with $N$ spatial orbitals. On a classical computer, for a ...
6
votes
Accepted
The correlation energy from frozen natural orbtials (FNOs) using CCSD and MPBT(2)?
The idea in the FNO method is to do a MP2 calculation for the one-particle density matrix and diagonalize it to get the natural orbitals (NOs) and natural orbital occupation numbers (NOONs).
So, ...
- 20k
5
votes
Are there interesting applications of estimating the energy for generalizations of the Heisenberg model?
When you have more than two Pauli operators in a single term, you can model multipolar terms, as described in this paper:
... multipolar correlators of order $p=1$ (spin, dipolar), $p=2$ (quadrupolar)...
5
votes
Accepted
How to solve time-dependent Schrodinger equation and plot trajectory on Bloch sphere?
The angles $\phi$ and $\theta$ never contain a non-zero imaginary part (they are always purely real numbers). The general solution to Eq. 1 is:
$$
\tag{1}
|\Phi(t)\rangle = e^{-\textrm{i}H t} | \Phi(0)...
4
votes
Accepted
Are there interesting applications of estimating the energy for generalizations of the Heisenberg model?
It is probably worth mentioning that, in the context of strongly correlated electron system / antiferromagnetism / superexchange, the spin-spin interactions arise from perturbation theory. In the ...
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4
votes
A matrix form used in the Quantum Annealer Eigensolver (QAE)
Introduction
The TDA (Tamm-Dancoff approximation) uses only the $A$ matrix, which is the upper-left block of the full TD-DFT matrix that was provided by Tyberius here, in his answer to your question ...
3
votes
Is a D-Wave quantum computer able to do TD-DFT calculations?
Any computation that can be solved on an ordinary classical computer can in theory be turned into a QUBO problem.
This includes TD-DFT calculations. We know this because the the 2-local Hamiltonian ...
2
votes
Is there any useful application to estimating the expectation value for an Ising model without magnetic field?
"I know that one "hot question" about the Ising model is to be able to find its ground state. However this ground state in the absence of magnetic field is necessarily a tensor product (...
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