Skip to main content
Quantum Computing

Questions tagged [continuous-variable]

Ask Question

Continuous-variable quantum computing is a type of quantum computing that makes use of physical observables, like the strength of an electromagnetic field, whose numerical values belong to continuous intervals.

42 questions
Newest Active Bountied Unanswered
Filter by
Sorted by
Tagged with
5 votes
1 answer
216 views

It is well known (arXiv) in continuous variable (CV) quantum information processing that an $N$-mode CV system whose dynamics are entirely Gaussian can be simulated efficiently with a classical ...
atman's user avatar
  • 169
1 vote
1 answer
236 views

Why are there significantly fewer algorithms for continuous quantum computation compared to discrete quantum computation?
Lawerence's user avatar
  • 133
3 votes
1 answer
389 views

I am a computer scientist. When I learned quantum information for the first time (in the circuit model, with qubits), I was presented four postulates that described mathematically (i) the possible ...
shashvat's user avatar
  • 927
3 votes
0 answers
61 views

I am struggling to understand the concept of updating angles in a parameterized algorithm. Assume I have an objective function $x^2+1$ that I want to optimize using QAOA which can handle continuous ...
34341's user avatar
  • 31
1 vote
0 answers
98 views

I have some combinatorial optimization problems which I would like to analyze using QAOA. These problems are coming from various applications in scientific computing such as solving PDEs. Some of ...
user82261's user avatar
  • 315
1 vote
1 answer
86 views

Often algorithms utilize an ansatz $V(a)$ and rely on a classical optimization scheme over a Hamiltonian loss function $L(V(a))$ in order to find the optimal parameters $a$. Due to many factors such ...
consthatza's user avatar
  • 361
1 vote
0 answers
158 views

I am training a variational quantum circuit to learn distributions: given data $s(\vec{\lambda})$, what is the probability distribution for the parameterisation $\vec{\lambda}$, i.e. the posterior ...
JoJo's user avatar
  • 109
2 votes
0 answers
171 views

Let's say I have the covariance matrix for a 4-mode system, $\sigma$, which is an $8 \times 8 $ matrix (the first moments are zero). I want to calculate the expectation value for an operator, for ...
Bard's user avatar
  • 337
8 votes
1 answer
352 views

If I understand correctly, the discrete and continuous variable (CV) version of quantum computation are equivalent. However, the continuous aspect of the CV model makes me wonder to what extent can ...
Mauricio's user avatar
  • 2,541
5 votes
2 answers
4k views

I know what QKD is, as a concept but I recently found papers mentioning continuous-variable quantum key distribution , and discrete-variable quantum key distribution . So I would like to know what is ...
user206904's user avatar
  • 339
3 votes
1 answer
396 views

I was recently reading about how Xanadu made a scalable, room-temperature-operating quantum computer using photons as qubits (see this link). It said that in the logic gates, it entangles two photons ...
Blue Herring's user avatar
  • 133
4 votes
0 answers
95 views

We know that a universal gate set for CV quantum computation is that of squeezing, beam splitters, and some nonlinear gate (e.g. this answer). We also know from Knill, Laflamme, and Milburn that ...
Quantum Mechanic's user avatar
  • 4,884
7 votes
1 answer
385 views

I read about the photonic QC Jiŭzhāng that showed quantum advantage by Gaussian boson sampling. I read that boson sampling itself is a sub-universal technique of QC (where they use single-photon ...
ile2N's user avatar
  • 155
4 votes
0 answers
91 views

In this question of a few days ago, it was raised the question about the similarities or differences between the notion of universality in discrete-variable (DV) quantum computers and continuous-...
RMPsp's user avatar
  • 41
4 votes
0 answers
44 views

I've heard that you run up against the very large constant factors when comparing run times of quantum and classical computers -- things simply take much longer in a carefully controlled quantum setup ...
mikanim's user avatar
  • 317
3 votes
0 answers
128 views

In this excellently answered question 'How are gates implemented in a continuous-variable quantum computer?' the typical gates for CV quantum computing were listed and described. In particular for ...
East's user avatar
  • 131
5 votes
1 answer
741 views

Background I am curious to learn more about any work that has been done regarding quantum systems that deal with infinite values. I am primarily interested in photonic quantum computing; however I am ...
user820789's user avatar
  • 3,440
2 votes
1 answer
1k views

Can anyone help me to find the mean value of the displacement operator $$D(\alpha) = \exp( \alpha a^\dagger -\alpha^* a)$$ for a Coherent State $\left|\beta\right> = D\left(\beta\right)\left|0\...
user8655's user avatar
  • 39
8 votes
1 answer
520 views

We know that the Wigner function of a Gaussian quantum state is (up to a constant) a Gaussian distribution. The first moment and the covariance of this distribution uniquely specify a quantum state. ...
taper's user avatar
  • 203
7 votes
1 answer
1k views

Qubit and qumode are different forms of quantum computation. But most existing quantum computers/chips seems to be of discrete variables. I heard that a group chose qubit for a quantum optical ...
raycosine's user avatar
  • 900
21 votes
1 answer
686 views

It seems to be a widely held belief within the scientific community that it is possible to do "universal, fault-tolerant" quantum computation using optical means by following what is called "linear ...
rrtucci's user avatar
  • 689