Questions tagged [google-sycamore]
A 54-qubit superconducting quantum processor by Google Quantum AI which is claimed to have been used to demonstrate quantum computational supremacy.
37
questions
1
vote
1
answer
47
views
Current situation of quantum computing with respect to physical vs logical qubits
As an example I'm going to start with Google and IBM. Google has the Sycamore processor right now with 53 physical qubits. However I haven't found any info on how many logical qubits it can actually ...
- 89
2
votes
1
answer
233
views
Is there something wrong with cross-entropy benchmarking, or is it still considered as a reasonable path towards quantum supremacy?
My question is strongly related with this one. Google's quantum supremacy claim uses Random Circuit Sampling. The principle is the following one: a realistic noise model for random circuits performed ...
- 5,354
1
vote
2
answers
426
views
Sycamore 2 versus Osprey
Google recently hit key milestone by reducing errors: https://www.nature.com/articles/d41586-023-00536-w
I would like to know why Google's QPU had way fewer qubits than IBM's Osprey and if IBM also ...
- 296
8
votes
0
answers
278
views
What is a gate-level circuit used in the 2022 Jafferis et al. experiment on Sycamore?
A recently published Nature paper of Jafferis et al. describes an experiment with a handful of qubits performed on Google's Sycamore processor to explore the SYK model in the context of AdS/CFT and ...
- 10.7k
7
votes
1
answer
264
views
Publicly available samples for quantum circuits and/or simulators
With Yosi Rinott and Tomer Shoham we studied various statistical aspects of samples coming from NISQ computers.
My question is about available data consisting of samples from NISQ computers
We would ...
- 201
15
votes
1
answer
493
views
Status of Google's quantum supremacy claim 2022
More than a year ago a couple of scientists made a splash by presenting a classical algorithm that took less than a week to simulate Sycamore's circuits on a small GPU cluster. Also, their simulations ...
- 2,359
2
votes
0
answers
86
views
Understanding the supremacy regime plot in Google's "Quantum supremacy using a programmable superconducting processor"
I was going through the Google's 2019 paper & had difficulties regarding some details.
How are they calculating XEB in quantum supremacy regime? To calculate the XEB,we also need the ideal ...
- 41
8
votes
0
answers
179
views
How can time crystals be useful in qRAM design?
A time crystal is a phase of a matter which is ordered in time, similar to classical crystals which are ordered spatially. In other words, the structure of a time crystal is ever-changing but with ...
- 13.6k
6
votes
1
answer
554
views
What is the basic hardware gate library in the IBM & google?
I need to know what is the basic hardware gate library in hardware IBM and Google? I mean, which one of the gates can be implemented directly in the hardware. I would be very grateful if everyone ...
- 169
2
votes
1
answer
365
views
Can Google Sycamore's benchmark for quantum supremacy be simulated on Qiskit?
In 2019, Google claimed that they have achieved quantum supremacy/advantage with their 53 qubit quantum processor Sycamore. The paper is here. But I have not even been able to find what their ...
- 2,202
3
votes
1
answer
157
views
What determines the repetition rate in Google's Weber datasheet?
The second page of the datasheet of Google's Weber system mentions a repetition rate. How is this repetition rate calculated?
https://quantumai.google/hardware/datasheet/weber.pdf
I understand that ...
- 125
1
vote
0
answers
390
views
Does a quantum computer exist today? [closed]
I agree that this may not be an easy question to answer.
But lately, I increasingly come across the fact that many news materials and research papers in the field of quantum technologies say that at ...
- 451
2
votes
2
answers
194
views
Is there a quantum processor with physically implemented Toffoli gate?
Recently, I came across the article Realization of efficient quantum gates with a superconducting qubit-qutrit circuit where its authors proposed a physical implementation of three qubits quantum ...
- 13.6k
6
votes
3
answers
2k
views
How are the IBM's and Google's Hadamard gates fabricated and operated?
There are thousands of articles, books and web sites describing the Hadamard Gate from a theoretical point of view.
But I haven't been able to find any photo about any real implementeation of a ...
- 163
1
vote
1
answer
111
views
Simulating noise of googles quantum computers
Is there a way to simulate the noise of googles quantum computers using circ? In the same way that any of IBM's computers can be simulated using different backends?
...
- 363
2
votes
0
answers
41
views
When we do a linear fit, what is the correlation coefficient of the estimated parameters?
In Google's quantum supremacy experiment, supplementary Section VIIIH, they calculate the correlation coefficient of the linear fit coefficients $p_0$,$p_1$. I can't figure out the definition of this ...
- 429
4
votes
1
answer
325
views
Do all physical architectures for quantum computers use the same universal gate sets?
Now I have understood that physical implementation of quantum computer need a universal quantum gate set like Clifford+T to realize any unitary quantum gate. However, I don't know if it is all the ...
- 457
10
votes
1
answer
692
views
Why Google has used $\sqrt{X}$ and $\sqrt{Y}$ instead of $X$ and $Y$ in supremacy experiment?
In supremacy experiment Google has used $\sqrt{X}$ and $\sqrt{Y}$ as two of their single qubit gates (paper).
So My questions are:
Is there any specific reason for choosing these gates and not $X$...
- 313
3
votes
1
answer
143
views
What is the role of choosing the single-qubits randomly in Google quantum supremacy experiment?
In supremacy paper and part D of section VII of supplementary information (below), it is said that there is a pseudo-random number generator that is initialized with a seed called $s$; And then the ...
- 313
7
votes
1
answer
327
views
What did exactly Google do in simulating a random quantum circuit on a classical computer in supremacy experiment?
I've been working on Google quantum supremacy paper for quite some time now and I have a problem in understanding how exactly they simulate their actual random quantum circuit on a classical computer.
...
- 313
2
votes
1
answer
76
views
In Google's Quantum Supremacy experiment, what if we use $\theta=45°$ for two-qubit $f_{sim}$ gates?
In Google's Quantum Supremacy experiment, they use $f_{sim}$(fermionic-simulation) gates with $\theta=90°$ and $\phi=30°$ as their two-qubit gates. What if we use $\theta=45°$ for the two-qubit $f_{...
- 429
18
votes
1
answer
4k
views
Which subatomic particle does each company use in quantum computing?
Probably each company (Google, Amazon, Intel, IBM, Microsoft, D-Wave and so on) uses a mix of subatomic particles and technologies. I would like to know which particles/technologies are used by each ...
3
votes
1
answer
270
views
Where are the physical gates in the Google processor?
Google's article Quantum supremacy using a programmable superconducting processor states that the processor "53 qubits, 1,113 single-qubit gates, 430 two-qubit gates, and a measurement on each qubit, ...
- 621
5
votes
1
answer
258
views
Can we conclude that errors on Sycamore are Poisson-distributed Pauli errors?
In Martinis' recent Caltech lecture on the Sycamore paper, he appears to make much of the fact that FIG. 4 of the paper show straight-line fidelity - that is, the fidelity decreases log-linearly with ...
- 10.7k
4
votes
2
answers
240
views
How exactly is solving the random circuit sampling problem a computation in the Church-Turing thesis sense?
Note: This has been cross-posted to CS Theory SE.
If we assume $\mathsf{BQP} \neq \mathsf{BPP}$, then we can say with reasonable certainty that Google's random sampling experiment falsifies the ...
- 17.2k
4
votes
1
answer
636
views
Making sense of the Sycamore's computing prowess - power consumption
I came here after reading about the announcement regarding the Sycamore processor and Google's Quantum Supremacy claim. I am hung up on several key things and I am hoping that I could find those ...
- 43
21
votes
2
answers
4k
views
What does Google's claim of "Quantum Supremacy" mean for the question of BQP vs BPP vs NP?
Google recently announced that they have achieved "Quantum Supremacy": "that would be practically impossible for a classical machine."
Does this mean that they have definitely proved that BQP ≠ BPP ?...
- 655
7
votes
1
answer
420
views
Why does Google's quantum processor outperform IBM's?
I understand that both have 53 qubit devices, yet it is Google that has demonstrated quantum supremacy (although IBM refutes this!). I'm not sure if this is true but it seems like IBM cannot replicate ...
- 2,597
13
votes
3
answers
684
views
Why do the IBM and Google processors both have 53 qubits?
As I understand from this IBM post both the IBM and Google teams have independently built 53-qubit processors. What is the significance of the number 53? It is purely coincidental, or is there a ...
- 233
7
votes
1
answer
279
views
Are 20 repetitions of Sycamore's one- and 2-qubit gates sufficient to produce a uniformly random state?
In the answer to this question about random circuits, James Wootton states:
One way to see how well we [fully explore the Hilbert space] is to focus on just randomly producing $n$ qubit states. ...
- 10.7k
5
votes
3
answers
3k
views
Quantum Supremacy: Some questions on cross-entropy benchmarking
I was skimming through the Google quantum supremacy paper but got stuck on this section:
For a given circuit, we collect the measured bit-strings $\{x_i\}$ and compute the linear XEB fidelity [24-26, ...
- 107
10
votes
2
answers
543
views
Number of qubits to achieve quantum supremacy?
Google's Sycamore paper describes achieving quantum supremacy on a $53$-qubit quantum computer. The layout of Sycamore is $n=6\times 9=54$ nearest neighbors, with one qubit nonfunctional. They apply ...
- 10.7k
5
votes
2
answers
242
views
Location of "bad" qubits on Sycamore
The Sycamore paper from Google notes that Sycamore is a $54$-qubit quantum processor, but for their experiments only $53$ qubits were working.
The "bad" qubit was on the edge of the array.
Is ...
- 10.7k
6
votes
1
answer
786
views
Understanding Google's “Quantum supremacy using a programmable superconducting processor” (Part 3): sampling
In Google's 54 qubit Sycamore processor, they created a 53 qubit quantum circuit using a random selection of gates from the set $\{\sqrt{X}, \sqrt{Y}, \sqrt{W}\}$ in the following pattern:
...
- 17.2k
9
votes
1
answer
1k
views
Understanding Google's “Quantum supremacy using a programmable superconducting processor” (Part 2): simplifiable and intractable tilings
In Google's 54 qubit Sycamore processor, they created a 53 qubit quantum circuit using a random selection of gates from the set $\{\sqrt{X}, \sqrt{Y}, \sqrt{W}\}$ in the following pattern:
...
- 17.2k
12
votes
2
answers
1k
views
Understanding Google's “Quantum supremacy using a programmable superconducting processor” (Part 1): choice of gate set
I was recently going through the paper titled "Quantum supremacy using a programmable superconducting processor" by NASA Ames Research Centre and the Google Quantum AI team (note that the paper was ...
- 17.2k
4
votes
2
answers
374
views
Do quantum supremacy experiments repeatedly apply the same random unitary?
It is my understanding that, given a quantum computer with $n$ qubits and a way to apply $m$ single- and 2-qubit gates, quantum supremacy experiments
Initialize the $n$ qubits into the all-zero's ket ...
- 10.7k