Records |
Author |
Prevedel, Robert; Hamel, Deny R.; Colbeck, Roger; Fisher, Kent; Resch, Kevin J. |
Title |
Experimental investigation of the uncertainty principle in the presence of quantum memory and its application to witnessing entanglement |
Type |
Journal Article |
Year |
2011 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat. Phys. |
Volume |
7 |
Issue ![sorted by Issue field, descending order (down)](img/sort_desc.gif) |
10 |
Pages |
757-761 |
Keywords |
fromIPMRAS |
Abstract |
Heisenberg's uncertainty principle provides a fundamental limitation on the ability of an observer holding classical information to predict the outcome when one of two measurements is performed on a quantum system. However, an observer with access to a particle (stored in a quantum memory) which is entangled with the system generally has a reduced uncertainty: indeed, if the particle and system are maximally entangled, the observer can perfectly predict the outcome of whichever measurement is chosen. This effect has recently been quantified in a new entropic uncertainty relation. Here we experimentally investigate this relation, showing its effectiveness as an efficient entanglement witness. We use entangled photon pairs, an optical delay line serving as a simple quantum memory and fast, active feed-forward. Our results quantitatively agree with the new uncertainty relation. Our technique acts as a witness for almost all entangled states in our experiment as we obtain lower uncertainties than would be possible without the entangled particle. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
|
Approved |
no |
Call Number |
RPLAB @ gujma @ |
Serial |
821 |
Permanent link to this record |
|
|
|
Author |
Fuchs, G. D.; Burkard, G.; Klimov, P. V.; Awschalom, D. D. |
Title |
A quantum memory intrinsic to single nitrogen–vacancy centres in diamond |
Type |
Journal Article |
Year |
2011 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat. Phys. |
Volume |
7 |
Issue ![sorted by Issue field, descending order (down)](img/sort_desc.gif) |
10 |
Pages |
789-793 |
Keywords |
fromIPMRAS |
Abstract |
A quantum memory, composed of a long-lived qubit coupled to each processing qubit, is important to building a scalable platform for quantum information science. These two qubits should be connected by a fast and high-fidelity operation to store and retrieve coherent quantum states. Here, we demonstrate a room-temperature quantum memory based on the spin of the nitrogen nucleus intrinsic to each nitrogen–vacancy (NV) centre in diamond. We perform coherent storage of a single NV centre electronic spin in a single nitrogen nuclear spin using Landau–Zener transitions across a hyperfine-mediated avoided level crossing. By working outside the asymptotic regime, we demonstrate coherent state transfer in as little as 120 ns with total storage fidelity of 88±6%. This work demonstrates the use of a quantum memory that is compatible with scaling as the nitrogen nucleus is deterministically present in each NV centre defect. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
|
Approved |
no |
Call Number |
RPLAB @ gujma @ |
Serial |
823 |
Permanent link to this record |
|
|
|
Author |
Hosseini, M.; Campbell, G.; Sparkes, B. M.; Lam, P. K.; Buchler, B. C. |
Title |
Unconditional room-temperature quantum memory |
Type |
Journal Article |
Year |
2011 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat. Phys. |
Volume |
7 |
Issue ![sorted by Issue field, descending order (down)](img/sort_desc.gif) |
10 |
Pages |
794-798 |
Keywords |
fromIPMRAS |
Abstract |
Just as classical information systems require buffers and memory, the same is true for quantum information systems. The potential that optical quantum information processing holds for revolutionizing computation and communication is therefore driving significant research into developing optical quantum memory. A practical optical quantum memory must be able to store and recall quantum states on demand with high efficiency and low noise. Ideally, the platform for the memory would also be simple and inexpensive. Here, we present a complete tomographic reconstruction of quantum states that have been stored in the ground states of rubidium in a vapour cell operating at around 80 °C. Without conditional measurements, we show recall fidelity up to 98% for coherent pulses containing around one photon. To unambiguously verify that our memory beats the quantum no-cloning limit we employ state-independent verification using conditional variance and signal-transfer coefficients. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
|
Approved |
no |
Call Number |
RPLAB @ gujma @ |
Serial |
824 |
Permanent link to this record |
|
|
|
Author |
Gao, Jie; McMillan, James F.; Wong, Chee Wei |
Title |
Nanophotonics: Remote on-chip coupling |
Type |
Journal Article |
Year |
2012 |
Publication |
Nature Photonics |
Abbreviated Journal |
Nat. Photon. |
Volume |
6 |
Issue ![sorted by Issue field, descending order (down)](img/sort_desc.gif) |
1 |
Pages |
7-8 |
Keywords |
fromIPMRAS |
Abstract |
Scientists have demonstrated strongly coupled photon states between two distant high-Q photonic crystal cavities connected by a photonic crystal waveguide. Remote dynamic control over the coupled states could aid the development of delay lines, optical buffers and qubit operations in both classical and quantum information processing. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
|
Approved |
no |
Call Number |
RPLAB @ gujma @ |
Serial |
779 |
Permanent link to this record |
|
|
|
Author |
Pile, David |
Title |
How many bits can a photon carry |
Type |
Journal Article |
Year |
2012 |
Publication |
Nature Photonics |
Abbreviated Journal |
Nat. Photon. |
Volume |
6 |
Issue ![sorted by Issue field, descending order (down)](img/sort_desc.gif) |
1 |
Pages |
14-15 |
Keywords |
fromIPMRAS |
Abstract |
Quantum physics offers a way to enhance the amount of information a photon can carry, with potential applications in optical communication, lithography, metrology and imaging. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Summary Language |
|
Original Title |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
|
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
View from... OSA Frontiers in Optics 2011: How many bits can a photon carry? |
Approved |
no |
Call Number |
RPLAB @ gujma @ |
Serial |
780 |
Permanent link to this record |