Topic
Quantum capacity
20 records: 14 unsolved, 6 solved. Filter the catalog by this topic →
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Finite-energy superactivation of Gaussian amplifiers and additive-noise channels
Is there a single-mode phase-insensitive Gaussian amplifier or additive-noise channel of zero finite-energy quantum capacity that acquires positive finite-energy quantum capacity when used in parallel with a two-mode positive-partial-transpose Gaussian channel…
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Channels superactivated by antidegradable helpers
What necessary and sufficient structural conditions characterize the finite-dimensional channels of zero quantum capacity, and separately those of zero private capacity, that acquire a positive capacity of the same kind when used in parallel with some antidegradable…
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Zero two-way quantum capacity of endpoint Holevo–Werner channels
Is the two-way assisted quantum capacity of the Holevo–Werner channel \(\mathcal W_d\) zero for every integer \(d\geq3\)?
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Strong converse for the quantum capacity of a general channel
Does every finite-dimensional memoryless quantum channel obey the strong converse at its unassisted quantum capacity?
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All-code exponential strong converse for degradable channels
Does every finite-dimensional degradable quantum channel satisfy an all-code exponential strong converse for quantum communication at its quantum capacity?
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Exponential strong converse for transpose-degradable channels
Does every finite-dimensional transpose-degradable channel satisfy an exponential strong converse for quantum communication at its single-letter quantum capacity?
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Quantum capacity of a bosonic thermal attenuator
What is the unassisted quantum capacity of a single-mode thermal attenuator at every strictly positive finite environment temperature?
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Two-way quantum capacity: amplitude-damping channel
What is the two-way quantum capacity \(\mathcal{Q}_2(\mathcal A_p)\) of the qubit amplitude-damping channel
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Two-way quantum capacity of a thermal amplifier
What is the two-way quantum capacity of a thermal amplifier for every gain and thermal noise level?
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Unassisted quantum capacity of a thermal amplifier
What is the unassisted quantum capacity of a thermal amplifier for every gain and thermal noise level?
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Quantum capacity of higher-dimensional depolarizing channels
What is the unassisted quantum capacity of a depolarizing channel in every finite dimension \(d\geq3\)?
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Squashed entanglement of the qubit depolarizing channel
What is the squashed entanglement \(E_{\mathrm{sq}}(\Lambda_p)\) of the qubit depolarizing channel, defined for a mixing parameter \(p\in[0,1]\) by
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Computability of ordinary quantum capacity
Is the ordinary unassisted quantum capacity a computable function of a finite description of a finite-dimensional quantum channel?
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Positivity threshold for thermal-attenuator quantum capacity
For \(0<\eta<1\) and \(0<\nu<\infty\), let the single-mode bosonic thermal attenuator be
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Energy-constrained quantum capacity of a thermal attenuator
For \(0<\eta<1\) and \(0<\nu<\infty\), let the single-mode bosonic thermal attenuator be
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Universal finite truncation of quantum and private capacities
Do there exist channel-independent finite integers \(m_Q\) and \(m_P\) that determine, respectively, the quantum capacity and the private classical capacity of every finite-dimensional quantum channel?
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Exactly solvable nondegradable quantum channels
Does there exist a finite-dimensional quantum channel that is neither degradable nor antidegradable and whose unassisted quantum capacity is known exactly?
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Quantum capacity of the Gaussian random-displacement channel
What is the unconstrained, unassisted quantum capacity of the single-mode Gaussian random-displacement channel?
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Quantum capacity of a qubit Pauli channel
What is the quantum capacity \(\mathcal{Q}(\Lambda_{\mathbf p})\) of the qubit Pauli channel defined by
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Capacity-achieving codes for amplitude damping
What is the constructive quantum code for achieving the quantum capacity \(\mathcal{Q}(\mathcal A_p)\) of the qubit amplitude-damping channel
Solved