Questions tagged [simulation]
For questions about simulating either quantum computers or simulating things on quantum computers.
414 questions
1 vote
1 answer
68 views
stim: why would order of CNOT operations affect detectors
I have two circuits (below) : first works fine (no complaints from stim); second comes back with a "non-deterministic detector" error. The difference between the two circuits is that the ...
- 2,994
2 votes
1 answer
137 views
stim : confusion about the use of observables
The role of adding observables is not clear to me. Here are some points of confusion : (1)From the circuit I generate a detector error model using dem from which I generate two matrices (pcm and lcm) ...
- 2,994
0 votes
1 answer
110 views
stim: understanding DEM probability calculations
I'm trying to understand how the probabilities in a stim DEM are calculated. I tried three simple cases; I understand the first, but can't seem to go beyond that : case 1: I understand the ...
- 2,994
1 vote
2 answers
169 views
what is the difference between "memory" circuit noise simulations and other types
When I see performance curves of codes/decoders in papers (logical error rate vs physical error rate) I thought I understood what they represent (making the analogy to the classical version). When (...
- 2,994
1 vote
2 answers
147 views
stim : how to control the structure of detector error model decoder matrix
I'm interfacing stim to my (custom) decoder. My decoder expects a parity check matrix and probabilities; similar to a BP-OSD decoder's input. To go from error detect model to these inputs I use a ...
- 2,994
1 vote
1 answer
76 views
stim : what (else) goes into defining a detector error model
I understand what should go into the model given a syndrome measurement circuit with error sources. What I'm trying to understand what else gets added to it. Some papers add one or two "error ...
- 2,994
3 votes
2 answers
61 views
Efficient training strategies for large-scale QAOA (≈100 qubits) on IBM backends
I'm having trouble running QAOA on real IBM backends. I want to solve an optimization problem using QAOA with around 100 or more logical qubits on ibm_kingston, to see how far current devices can be ...
- 97
4 votes
2 answers
156 views
Stim: What is a good workflow for adding non-trivial detectors?
I have been using Stim for a while now. Still, I find it particularly difficult to add non-trivial detectors in Stim (such as the in-place access of the Y-Basis Gidney introduced), and I’m wondering ...
- 324
3 votes
1 answer
120 views
can re-encoding help lower logical error rate
For simplicity, assume the code is a CSS code and we're working with X stabilizers (Hx) and logicals (Lx). To estimate the logical error rate of this code, here are the steps I see taken by open ...
- 2,994
4 votes
1 answer
150 views
Verify correcteness of syndrome extraction procedures in STIM
My questions arised basically from playing around with the STIM "getting_started" notebook, regarding the part on the rotated surface code. There 3d syndrome extraction rounds are performed ...
- 43
0 votes
0 answers
84 views
Using Stim to simulate multiple rounds of logical operations
My goal is using Stim to simulate a fault-tolerant logical circuit, which have multiple rounds of logical operation -> syndrome extraction -> decoder. During my trials, I find that Stim cannot ...
- 11
4 votes
1 answer
266 views
How to run Qiskit AerSimulator with GPU (A100) in Google Colab?
I'm trying to run quantum circuit simulations with Qiskit Aer using GPU acceleration (specifically an NVIDIA A100) in Google Colab Pro. Here's a simplified example I'm running: ...
0 votes
1 answer
68 views
Advantage of Clifford circuit simulation using graph state simulator
I have been recently reading the classic paper https://journals.aps.org/pra/abstract/10.1103/PhysRevA.73.022334 The paper claims a time complexity of $O(N \log{N} M)$ where $N$ is the number of qubits ...
2 votes
1 answer
103 views
how is measurement modelled in tableaux simulation
I'm reading through a stim overview paper and found a description of how a (single qubit) measurement is carried through a tableaux : Gidney paper,(page 9). I couldn't find another reference for this ...
- 2,994
0 votes
1 answer
134 views
stim : how does ordering/grouping of CNOT's affect circuit noise
I have a syndrome extraction circuit that uses $N$ CNOT's altogether. The CNOT connection is the standard way of having data qubits as control and ancilla qubits as targets. These can in principle be ...
- 2,994