Unanswered Questions
79 questions with no upvoted or accepted answers
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What is an electro-optic switch?
I found an implementation of a CNOT in photonic QC and I just couldn't find any info on a component named "electro-optic switch"
What does it do exactly?
How does it work?
The ...
- 93
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Clean way of approximating an oscillator by a qubit
Let me consider a (quantum) Harmonic oscillator of (bare) Hamiltonian:
$$H_0=\frac{p^2}{2m}+\frac{1}{2} m \omega^2 x^2$$
(I can add to it an anharmonicity $V=\alpha x^4$ if necessary for the purpose ...
- 1,962
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How to do the counting when computing the fault tolerant threshold of quantum codes?
Here, I want to ask a basic question about how to compute the fault tolerance threshold of quantum codes. As I know, maybe, the most usual way is to do some simulations. Howvever, I am more intersted ...
glS♦
- 26.9k
4
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Is there a measurable of entanglement for a many-body system?
After having a discussion with a quantum computing colleague, a question came up: is there any meaningful way to measure entanglement (or something related to it) in a solid-state many body system ...
- 537
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Form and effect of the intrinsic Hamiltonian on the IBM machines
I want to understand the form of the intrinsic Hamiltonian of the IBM machines, such as ibmq_16_melbourne, and how this affects the data I get out when waiting ...
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Is generating usable entanglement difficult?
I'm a theorist and I assume that I can use entanglement resources for practical use freely, but is this really the case? Is generating entanglement and storing it for long enough periods of time such ...
- 17.8k
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What is the charging energy in relation to a superconducting transmon?
The transmon achieves its reduced sensitivity to charge noise by significantly increasing the ratio of the Josephson energy to the charging energy. What is this charging energy?
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Examples of temperature-dependent quantum channels
I am looking for examples of instances or families of quantum channels that arise out of an interaction of a quantum system with an environment having some temperature. For instance, the generalized ...
- 7,646
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Do we really apply both single-qubit and two-qubit gates in the same layer in experiments?
I'm doing experiments using superconducting computers, and my question is as follows:
Performing quantum gates requires isolating the coupling between a target qubit and other neighboring qubits.
To ...
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Individual processing of quantum circuit measurment results
When superconducting transmon qubits are measured with a readout pulse, the raw readout signal is demodulated, and results appear as clouds on the IQ plane, with one point in the cloud representing ...
- 1,360
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What does the $\sigma_z$ operator correspond to in the context of a Transmon qubit?
In the context of the transmon qubit and an LC circuit with a coupling capacitor and driving voltage.
We can write the charge operator $Q$ as $-iQ_{ZPF}\sigma_y$ (since we defined $Q$ using the ladder ...
- 24.8k
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Calculate Outputs of a Teleportation Circuit
In this question, I assume we use matrix representation to calculate what each output could be?
For example, for the middle qubit in state: $$|00\rangle$$
After the first Hadamard and CNOT gate (so ...
- 131
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How to quantify trace distance between two matrices representing two quantum optical networks?
This is my first post here, so I'm sorry if this question could be ill-formulated. I have performed measurements on a 12x12 optical quantum network, so that I have a stochastic matrix $P^{exp}$ where ...
glS♦
- 26.9k
3
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Are there any detailed designs for Quantum Computing hardware?
I am looking to analyze some quantum hardware designs, preferably superconducting and photonics, but I can't seem to find sources that give some detailed information. Can someone provide me designs ...
glS♦
- 26.9k
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What does "decoherence attenuates the density matrix" mean?
I'm reading the paper Implementation of the Quantum Fourier Transform. On page 4, they write
To a first approximation, decoherence during the course of the QFT attenuates the entire density matrix. ...
