Questions tagged [simulation]
For questions about simulating either quantum computers or simulating things on quantum computers.
335
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Is it possible to find out the number of timesteps taken by the mesolve/sesolve method in QuTip?
I am simulating a Quantum System in QuTip using qutip.sesolve. As far as I understand it, the solver propagates the state into the future using time steps of ...
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qiskit QAOA on Aer GPU giving errors
I am trying to run Qiskit QAOA algorithm on using aer simulator and device GPU. But I am not sure how to give this backend in the QAOA algorithm structure.
Here is ...
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54
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Phase shift on qiskit quantum teleportation simulation
I wonder in Qiskit why the phase shift occurred in my simulation and how I can turn it off.
I posted another question regarding the same simulation here, and while I tried to solve this on my own, I ...
2
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22
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Qiskit noisy FakeManila simulator + ZNE
I am trying to run a simple VQE calculation on H2 using FakeManila noise model and ZNE for error mitigation; see code below. The problem is that I can never reach not even close the ground electronic ...
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68
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Single-shot error correction for the surface code with measurement errors
I am trying to implement a single-shot error correction for the surface code with data + measurement errors (both with prob. p), using the (build-in) BP+OSD decoder. I am mostly following these papers:...
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75
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Most efficient way to calculate an expectation value of a noisy model in Qiskit
I want to classically simulate quantum circuits with noise. This noise can be a custom one (noise.NoiseModel()) or a fake quantum computer (...
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56
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Is it possible to simulate a quantum algorithm on a classical computer? [duplicate]
I am designing a quantum algorithm that I would like to simulate and test, but I need to be able to simulate it on a classical computer.
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Advantage of quantum computers over classical computers in fully modeling interactions between atoms?
I'm trying to better understand the advantage quantum computers offer in terms of their ability to more accurately model chemical reactions. As a way to come to a deeper understanding, my question is:
...
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How does depolarization error accumulate?
Here's my code to define the depolarization error using Qiskit, which included both one and two-qubit errors:
...
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Help me to find error in finding Cost Function for SSVQE algorithm [closed]
Q: Build SSVQE's cost function using the following observable: $$O=2II−2XX+3YY−3ZZ\,.$$
This cost function should take in parameters as input. Use the included variational form, with reference states $...
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Are quantum simulation results more accurate than real IBMQ device results?
Getting two different results from simulation and rel IBMQ device. Which is more accurate?
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Qudits in NISQ Devices: Benefits Beyond Dimensional Advantages?
It's clear from foundational research that qudits can provide an enhanced control of the Hilbert space over qubits, and I've encountered references that highlight improved robustness and noise ...
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What are the practical applications of quantum computing in engineering by the year 2030?
Are there any engineering problems that quantum computing can solve or simulate, and demonstrate a real advantage over conventional computing by the year 2030?
My primary interest is in the business ...
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Could a quantum computer simulate any system based on different types of logic? [duplicate]
Quantum computing is based on quantum mechanics (obviously) which has different logical rules than classical/Boolean logic.
However, does this mean that a quantum computer could simulate or process ...
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31
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Compiling pulses with time dependent $\sigma_x$ and $\sigma_y$ control
I have a Hamiltonian of the form:
$$
H = c_x(t) \sigma_x + c_y(t) \sigma_y$$
and I want to compile a pulse "P" that has both $\sigma_x$ and $\sigma_y$ control, with different time dependent ...
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Efficiently simulating a BQP circuit and polynomial hierachy collapse
If we were able to simulate a BQP (Bounded-error Quantum Polynomial time) circuit using a classical computer in an efficient manner, does it necessarily mean that the Polynomial Hierarchy (PH) would ...
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Can I simulate a quantum walk in fourier space?
I would like to simulate a simple quantum walk in Fourier space in Python. I am hoping just to run a 1D quantum walk with a simple Hadamard coin in Fourier space. Is this possible? Do I just need to ...
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51
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Why is Qiskit's QASM simulator giving me incorrect result with VQE?
In the code below, I am using VQE without noise to calculate the minimum expectation value of the two-qubit operator X^X. I get the correct result when I use statevector_simulator but do not get the ...
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Efficient classical simulation technique to execute this specific quantum circuit
I have a quantum circuit similar to the ones used in VQE methods. One difference is that the angles of the $R_y$ rotations are limited in the range $[0, 0.2]$ (and chosen randomly). In my case, I have ...
- 373
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How does the Qiskit AerSimulator performance scale with the circuit depth?
The performance of a full-statevector simulation by the Qiskit AerSimulator scales of course exponentially with the number of qubits, since the dimensionality of the Hilbert space where an $N$-qubits ...
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Can someone explain the behavior called "Aer fast expectation" of Qiskit simulators?
Earlier I asked a question on why statevector_simulator ignores the number of shots when calculating the expectation value of an operator using ...
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Subespace Search Variational Quantum Eigensolver (SSVQE) with contraints
I am trying to reproduce this paper: https://arxiv.org/pdf/2211.02302.pdf. However, I am having problems in getting the singlet first excited state (S1). The authors in the paper, they use the SSVQE ...
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Qiskit: Quantum program execution with aer and aer-gpu
I want to run my custom designed encryption algorithm on parallel GPUs and for that reason I am using qiskit-aer-gpu. Currently I am simulating on a single machine. ...
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Can simulations of a quantum algorithm on a classical computer out-perform a classical algorithm?
Has it ever been shown that simulation of a quantum algorithm (e.g., using PyQuil or something?) on a classical computer has out-performed a purely classical algorithm? From what I can tell the ...
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Confusion regarding hardness of BQP
Consider a polynomial time quantum circuit on $n$ qubits. The class of circuits under consideration encompasses the complexity class $\mathsf{BQP}$.
Now, say we have an $n-1$ qubit polynomial time ...
- 1,251
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3
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117
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Mysterious behavior from QisKit's Aer Simulator MPS - how to fix it?
I'm running QAOA with a large number of qubits (64 qubits), and I'm having some issue getting the job to progress. I've tried a few different simulators, but I'm not sure how to tune the settings to ...
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45
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Quantum circuit runtime
I want to estimate the execution time of some experiments, and I would be interested to know how the time needed to run a quantum circuit grows in function of the number of qubits and the parametric ...
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Quantum algorithms with few T gates?
Many existing quantum algorithms require millions or billions of T gates to reach a scale that is classically hard to simulate. However, existing Clifford + T circuits seem hard even with 100 or so T ...
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283
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Is that possible to simulate Grover's algorithm in quadratic time?
So it is clear that the Grover algorithm offers a quadratic speedup over the classical algorithms; my question is, is it known how to simulate Grover at the most quadratic time? To clarify my question,...
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143
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Expressibility and Entanglement Capability of the Parameterized Quantum Circuits
I am trying to calculate the expressibility and entangling capability of a quantum state resulting from a circuit as defined in reference I.
One of my attempts was to follow reference II which gives ...
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85
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what's the time complexity of the number of shots in simulator of qiskit
One question,
codes as follows:
backend = Aer.get_backend('qasm_simulator')
counts = execute(qc, backend=backend, shots=102400).result().get_counts()
when my ...
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Clifford element/tableau composition as matrix multiplication
Elements of the $n$-qubit Clifford group (or more precisely, elements of the projected $n$-qubit Clifford group, see Is the Clifford group finite?) may be represented as $2n \times 2n + 1$ binary-...
2
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2
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137
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GPU Access for qiskit-aer-gpu from Ubuntu VM
I have NVIDIA GeForce GT740 Graphics card installed on my host machine with Windows 10 OS. I have to simulate a cluster environment in order to run qiskit codes in parallel fashion. Before actual ...
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Simulating cross talk of quantum hardware
I am working on some experiments on the IBMQ Guadalupe machine. Since access to the real hardware is time consuming and limited, I am trying to simulate the errors that occur on real hardware to the ...
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31
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Qiskit: RGQFTMultiplier is giving wrong answers for 28 bits number multiplication with MPS simulator
I am using RGQFTMultiplier for multiplying two unsigned integers. Starting from simpler example of 2 qbits input, I reached 24 and all worked fine. I am using MPS as backend and my RAM is 32. However ...
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What is the most efficient way to run several simulations of parameterized quantum circuits in Qiskit?
Suppose I am given a parameterized quantum circuit in Qiskit: as an example, here I consider a ZZFeatureMap ansatz, commonly used for data embedding in quantum ...
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Qiskit: How much exact number of qbits simulator is capable of working with
My circuit is adding two 128 bits number and each input has been stored in 128 length quantum register (total 128*3 + carry in and out, 386). For calculation purpose I am using AER's different ...
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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 ...
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Does Gottesman-Knill theorem apply with any computational basis input?
On Wikipedia, the Gottesman-Knill theorem is said to state the following:
A quantum circuit using only the following elements can be simulated efficiently on a classical computer.
Preparation of ...
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2
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If sampling the output of $U_1U_2$ is easy, is sampling the output of $(U_1U_2)^\dagger$ also easy?
Let $U_1$ and $U_2$ be $n$-qubit unitaries, and denote by $P_{U_1U_2}(y \mid x) = |\langle y | U_1U_2 | x \rangle|^2$ the probability of measuring $y \in \{0,1\}^n$ on input $x \in \{0,1\}^n$. Suppose ...
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264
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How to convert a quantum circuit into a tensor network?
I need to perform tensor network contraction on a maxcut circuit, are there any resources or code available which converts maxcut circuit into a tensor network (preferably the adjacency list or any ...
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1
answer
158
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Exact expectation value of a quantum circuit simulated with the matrix product state method in qiskit
If I use the matrix product state method in Qiskit to simulate quantum circuits, I can obtain the exepctation value of an observable by using a finite amount of shots. Is there a way to obtain the ...
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How do I change the x and y axis on the results histogram for a ibmq_qasm.simulation resulting histogram?
Im following a textbook and when they ran the same circuit with the ibmq_qasm_simulator, their results histogram had computational basis state on the x axis and probability on the y axis, however my ...
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359
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Tensor network simulation of quantum circuits with Python
What are the best tensor network-based simulators libraries in Python?
In particular, I'm interested in calculating the expectation value of an observable measured at the end of a quantum circuit.
...
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Is there any quantum annealer simulator offered by DWave?
I am searching for quantum annealer simulator offered by DWave. I found classical solvers in dimod packages that implement simulated annealing, but I couldn’t find solver that simulates the real ...
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285
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How to get a noisy density matrix after partial measurements in Qiskit
I'm trying to study the effect of noise on a quantum system with partial measurements using Qiskit. Suppose I have $N + M$ qubits and I run a quantum circuit and measure $M$ of them. I want to know ...
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134
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What is the mathematical essence of Qiskit simulators?
As a newcomer to quantum computing, I have a question about the simulation of a quantum computer using Qiskit on a classical computer. Does Qiskit actually perform matrix manipulations in its ...
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71
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Is it possible to run pulse callibrated gates on a simulated ibm backend
Currently I am trying to test a quantum algorithm that consists of calibrated quantum gates on a circuit. It needs to stay this way because I would like to run the algorithm on a real backend in the ...
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130
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What is the computational cost of simulating a quantum circuit with matrix product states?
If we simulate Quantum circuits with the Matrix Product State (MPS) technique, the computational cost of the simulation depends on the entanglement in the circuit. How can I calculate this quantity ...
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How to calculate the Pauli Noise model of a physical gate operation?
I've seen literature and QuTip implementation of calculating a gate fidelity given the transformed density matrix, and in that case it uses a number of different initial states. My question however, ...
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