Unanswered Questions
107 questions with no upvoted or accepted answers
11
votes
0
answers
179
views
Anti-symmetrization on the lattice
Assume, I'm using a system of qubits to simulate a fermionic system.
If I'm using the second-quantized formalism (e.g. orbitals in quantum chemistry), the anti-symmetric nature of the fermionic wave ...
- 2,221
5
votes
0
answers
122
views
What is the classical cost of simulating an arbitrary quantum state?
The past couple of years has seen various groups claim quantum advantage/utility only to have their experiments efficiently simulated with classical methods, notably using tensor networks.
My question ...
glS♦
- 26.9k
5
votes
0
answers
662
views
Add noise_model when using 'ibmq_qasm_simulator' backend and provider.runtime.run() function
I am trying to test some qiskit code that employs readout-error mitigation using the ibmq_qasm_simulator backend and Qiskit Runtime. I am getting the backend as ...
- 51
5
votes
0
answers
158
views
Trotter error for bosons in various encodings
Mapping second-quantized bosonic modes onto qubits can be done using various encodings. Each of those have their pro et contra. Fewer qubits — more gates, and vice versa. Encoding an $N$-level bosonic ...
- 2,438
5
votes
0
answers
725
views
OpenFermion to Qiskit
Is there a direct way to go from an object generated in OpenFermion to objects usable in Qiskit? I can't find anything about any plugin.
It's not too hard to translate into pyQuil and then to Qiskit ...
5
votes
0
answers
54
views
What is the current research status in simulating many-particle systems from first principles?
There is a huge gap between basic physical laws and predicting many particle systems from first principles. It will be so amazing if we can predict most properties of many particle systems (from mass ...
- 171
5
votes
0
answers
105
views
Application of classical approximate optimization algorithm to bottlenecks of quantum computing
According to J. Gough, one of the bottlenecks in the current development of large-scale quantum computing may be the lack of our ability to simulate large scale quantum system, which is a NP-hard ...
5
votes
0
answers
578
views
Error: Simulation of "Quantum algorithm for linear systems of equations" for $4\times 4$ systems on Quirk (without SWAP) - Global phase
Following @DaftWullie's answer I tried to simulate the circuit given in Fig. 4 of the paper (arXiv pre-print): Quantum circuit design for solving linear systems of equations (Cao et al, 2012), on ...
- 17.8k
4
votes
0
answers
71
views
Is there a more efficient (pure-system bipartite) separability check than Qrack's?
Firstly, I am lead author and developer of unitaryfund/qrack, the open-source quantum computer simulator. We've had a method in the library, ...
- 91
4
votes
0
answers
179
views
Understanding the Gottesman-Knill Theorem
I come from a theoretical CS background, and I am trying to gain a better appreciation of the exact formal statement of the Gottesman-Knill theorem in terms that I am more familiar with. My question ...
- 541
4
votes
0
answers
228
views
Where can I find information about the differences between IBM simulator backends?
I'm an Msc student working on a quantum information project (VQEs on 4 qubits).
Our group is looking at different IBM simulators on the IBM platform, and have noticed that performance is different for ...
glS♦
- 26.9k
4
votes
0
answers
191
views
Apply a single-qubit channel between in between two circuits in Qiskit
Suppose, you have two parts of a circuit in Qiskit, qc1 and qc2 on any number of qubits such that the entire circuit is given by
...
- 959
4
votes
0
answers
58
views
Expectation value of a time evolved circuit in the non-Z basis
I am new to qiskit and have hit a roadblock in my calculation. Given the following circuit:
...
- 41
4
votes
0
answers
95
views
Simulation of algorithms with QFT on a classical computer
In paper The Quantum Fourier Transform Has Small Entanglement the authors showed that strong entanglement of qubits caused by QFT comes mainly from ordering the qubits. QFT itself prepares only weak ...
- 14.9k
4
votes
0
answers
33
views
Qiskit: efficient way to create bound circuits?
I am running an optimization problem whose objective function $F(a)$ requires measuring N variational circuits $V_i(a)$ at each evaluation.
So, roughly, I have created N parametric circuits and I do:
<...
- 361