Quantum communication is a generalization of quantum cryptography. It refers to protocols and techniques for transmission of an unknown quantum state (of a quantum system) from one place to another.
Questions tagged [communication]
89 questions
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What is a flying qubit?
DiVincenzo criteria for quantum communication mentions flying qubits:
a. The ability to interconvert stationary and flying qubits
b. The ability to faithfully transmit flying qubits between specified locations
So, what exactly is a flying qubit, and…
Amitabh Srivastava
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How many bits do Alice and Bob needs to compare to make sure the channel is secure in BB84?
I was trying to self-study qmc by reading the Quantum Computing A Gentle Introduction book, in section 2.4 it talks about the quantum key distribution protocol BB84. After (I thought) I understood it I went to work on exercise 2.9 and 2.10.
Ex. 2.9…
Sam
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Entanglement-assisted hashing bound for asymmetric depolarizing channels
I reading the paper EXIT-Chart Aided Quantum Code Design
Improves the Normalised Throughput
of Realistic Quantum Devices, which proposes the use of QTCs in order to do quantum error correction for realistic quantum devices whose error model can be…
Josu Etxezarreta Martinez
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Advances in Quantum Channel Capacity
I have been reading about the Quantum Channel Capacity and it seems to be an open problem to find such capacity in general. Quantum capacity is the highest rate at which quantum information can be communicated over many independent uses of a noisy…
Josu Etxezarreta Martinez
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The process for transferring qubits between locations
I understand that right now qubits are physical entities in a Quantum Computer and I am playing around on the IBM Quantum Computer as well as the Q# language and dipping my toes into the Quantum world for the first time.
I have read a lot of the…
Leigh Griffin
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How could a quantum network be constructed to handle 10,000 clients concurrently?
The C10k Problem is a classical computing problem whose name (C10k) is a numeronym for concurrently handling ten thousand connections.
How could a quantum network be constructed to handle 10,000 clients concurrently?
user820789
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What are examples of zero capacity quantum channels with Choi rank less than $d$?
All the currently known examples of quantum channels with zero quantum capacity are either PPT or anti-degradable. These notions can be conveniently defined in terms of the Choi matrix of the given channel:
A channel is said to be PPT if its Choi…
mathwizard
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Can superdense coding be made more efficient?
Superdense encoding allows us to transmit the information of two classical bits using a single qubit with a pre-shared Bell state qubit pair. We can duplicate the construct to transmit $2n$ classical bits using $n$ qubits. My question is: can we do…
czwang
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What is the quantum bandwidth of a planar array of noisy qubits, assuming free classical communication?
A common task to perform during quantum computation on the surface code is moving qubits from one place to another. There are standard ways to do this within the surface code, but I was wondering what the actual fundamental limits are. If we forget…
Craig Gidney
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What are "collective measurements", and how do they differ from "normal" measurements?
I am reading the paper Polar codes for classical-quantum channels
by Wilde and Guha, and it is stated the fact that collective measurements are necessary in order to aciheve the Holevo symmetric information as it can be seen from the HSW theorem.…
Josu Etxezarreta Martinez
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Does entanglement allow enhanced communication efficiency?
From what I gather, communication is not possible with quantum mechanics. With the experiment on teleportation, entanglement is referred to as coordination and not communication. However, my belief is that communication is taking place. For example,…
Jose
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Schumacher compression - comparing with Shannon compression
Background
Shannon's source coding theorem tells us the following. We shall consider a binary alphabet for simplicity. Suppose Alice has $n$ independent and identically distributed instances of a random variable $X\in \{0, 1\}$. Let us call this…
user1936752
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What is the practical interest of superdense coding?
When you enter the field of quantum communications, you run at some point into the concept of superdense coding.
Basically it is a way to encode classical bits on the qubits of a quantum channel, which sounds interesting in the first place to…
Mathias
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Can $2^n$ bits be sent with $n$ instances of quantum teleportation?
So, right now these are two pieces of information I've been told are correct:
Quantum teleportation can send a single qubit from Alice to Bob, with two classical bits
$n$ qubits can store $2^n$ classical bits of information
If both of these are…
rydwolf
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How could a global quantum network be realized?
This article from 2017 predicts the quantum internet by 2030. What are the biggest bottlenecks in the realization of a global quantum network (ie quantum internet)?
user820789
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