Resource requirements of private quantum channels
Year: 2005
Type: preprint
Abstract: Private quantum channels (PQCs) (quant-ph/0003101) and private quantum channels with entanglement (PQCEs) (quant-ph/0012077) have been studied in the recent past. We show the following. 1) A PQCE which can transmit any n-bit classical string must use n/2-qubits of entanglement. A matching upper bound is achieved by super dense coding which is a PQCE . 2) A PQCE which can transmit any n-qubit quantum state must use n-qubits of entanglement. A matching upper bound is achieved by teleportation which is also a PQCE . We also consider two-way multiple round PQCs (MPQC) and PQCEs (MPQCEs). We show that an MPQC which can transfer an n-qubit state must use n-bits of shared randomness. Also an MPQCE which can transfer an n-qubit state must use Omega(n) qubits of entanglement. Hence there is not much saving even when multile rounds are allowed.
Source: arXiv (Cornell University)
Author: Rahul Jain
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2791795340