scholarly journals The dynamic ligand field of a molecular qubit: decoherence through spin–phonon coupling

2020 ◽  
Vol 22 (20) ◽  
pp. 11249-11265 ◽  
Author(s):  
Ruben Mirzoyan ◽  
Ryan G. Hadt
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Room Temperature ◽  
Field Model ◽  
Quantum Information Processing ◽  
Design Principles ◽  
Ligand Field ◽  
Phonon Coupling ◽  
Chemical Design

A ligand field model highlights chemical design principles for the development of room temperature coherent materials for quantum information processing.

scholarly journals All-optical reversible single-photon isolation at room temperature

2021 ◽  
Vol 7 (12) ◽  
pp. eabe8924
Author(s):  
Ming-Xin Dong ◽  
Ke-Yu Xia ◽  
Wei-Hang Zhang ◽  
Yi-Chen Yu ◽  
Ying-Hao Ye ◽  
...  
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Insertion Loss ◽  
High Speed ◽  
Room Temperature ◽  
Quantum Information Processing ◽  
Single Photon ◽  
Electromagnetically Induced Transparency ◽  
All Optical ◽  
On Chip

Nonreciprocal devices operating at the single-photon level are fundamental elements for quantum technologies. Because magneto-optical nonreciprocal devices are incompatible for magnetic-sensitive or on-chip quantum information processing, all-optical nonreciprocal isolation is highly desired, but its realization at the quantum level is yet to be accomplished at room temperature. Here, we propose and experimentally demonstrate two regimes, using electromagnetically induced transparency (EIT) or a Raman transition, for all-optical isolation with warm atoms. We achieve an isolation of 22.52 ± 0.10 dB and an insertion loss of about 1.95 dB for a genuine single photon, with bandwidth up to hundreds of megahertz. The Raman regime realized in the same experimental setup enables us to achieve high isolation and low insertion loss for coherent optical fields with reversed isolation direction. These realizations of single-photon isolation and coherent light isolation at room temperature are promising for simpler reconfiguration of high-speed classical and quantum information processing.

scholarly journals Demonstration of a scalable, multiplexed ion trap for quantum information processing

2009 ◽  
Vol 9 (11&12) ◽  
pp. 901-919
Author(s):  
D.R. Leibrandt ◽  
J. Labaziewicz ◽  
R.J. Clark ◽  
I.L. Chuang ◽  
R.J. Epstein ◽  
...  
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Heating Rate ◽  
Room Temperature ◽  
Quantum Information Processing ◽  
Ion Trap ◽  
Trap Design ◽  
Large Numbers ◽  
Control Electronics ◽  
Trap Size

A scalable, multiplexed ion trap for quantum information processing is fabricated and tested. The trap design and fabrication process are optimized for scalability to small trap size and large numbers of interconnected traps, and for integration of control electronics and optics. Multiple traps with similar designs are tested with $^{111}$Cd$^+$, $^{25}$Mg$^+$, and $^{88}$Sr$^{+}$ ions at room temperature and with $^{88}$Sr$^+$ at 6 K, with respective ion lifetimes of 90 s, 300 $\pm$ 30 s, 56 $\pm$ 6 s, and 4.5 $\pm$ 1.1 hours. The motional heating rate for $^{25}$Mg$^{+}$ at room temperature and a trap frequency of 1.6 MHz is measured to be 7 $\pm$ 3 quanta per millisecond. For $^{88}$Sr$^{+}$ at 6 K and 540 kHz the heating rate is measured to be 220 $\pm$ 30 quanta per second.

Quantum Information Processing with NV centers at Room Temperature

2013 ◽  
Author(s):  
Peter C. Maurer ◽  
Georg Kucsko ◽  
Christian Latta ◽  
Liang Jiang ◽  
Norman Y. Yao ◽  
...  
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Room Temperature ◽  
Quantum Information Processing ◽  
Nv Centers

CONTROLLING SPIN COHERENCE WITH SEMICONDUCTOR NANOSTRUCTURES

2008 ◽  
Vol 22 (01n02) ◽  
pp. 111-112
Author(s):  
DAVID D. AWSCHALOM
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Electron Spin ◽  
Nuclear Spin ◽  
Room Temperature ◽  
Quantum Information Processing ◽  
Spin Dynamics ◽  
Spin Coherence ◽  
Electron Spin Dynamics ◽  
Coherent Spin

We present two emerging opportunities for manipulating and communicating coherent spin states in semiconductors. First, we show that semiconductor microcavities offer unique means of controlling light-matter interactions in confined geometries, resulting in a wide range of applications in optical communications and inspiring proposals for quantum information processing and computational schemes. Studies of spin dynamics in microcavities — a new and promising research field — have revealed novel effects such as polarization beats, stimulated spin scattering, and giant Faraday rotation. Here, we study the electron spin dynamics in optically-pumped GaAs microdisk lasers with quantum wells and interface-fluctuation quantum dots in the active region. In particular, we examine how the electron spin dynamics are modified by the stimulated emission in the disks, and observe an enhancement of the spin coherence time when the optical excitation is in resonance with a high quality ( Q ~ 5000) lasing mode.1 This resonant enhancement, contrary to expectations from the observed trend in the carrier recombination time, is then manipulated by altering the cavity design and dimensions. In analogy to devices based on excitonic coherence, this ability to engineer coherent interactions between electron spins and photons may provide novel pathways towards spin dependent quantum optoelectronics. In a second example, the nitrogen-vacancy (N-V) center in diamond has garnered interest as a room-temperature solid-state system not only for exploring electronic and nuclear spin phenomena but also as a candidate for spin-based quantum information processing. Spin coherence times of up to 50 microseconds have been reported for ensembles of N-V centers and a two-qubit gate utilizing the electron spin of a N-V center and the nuclear spin of a nearby C-13 atom has been demonstrated. Here, we present experiments using angle-resolved magneto-photoluminescence microscopy to investigate anisotropic spin interactions of single N-V centers in diamond at room temperature.2 Negative peaks in the photoluminescence intensity are observed as a function of both magnetic field magnitude and angle, and can be explained by coherent spin precession and anisotropic relaxation at spin-level anticrossings. Additionally, precise field alignment with the symmetry axis of a single N-V center reveals the resonant magnetic dipolar coupling of a single "bright" electron spin of an N-V center to small numbers of "dark" spins of nitrogen defects in its immediate vicinity, which are otherwise undetected by photoluminescence. Most recently, we are exploring the possibility of utilizing this magnetic dipole coupling between bright and dark spins to couple two spatially separated single N-V center spins by means of intermediate nitrogen spins. Note from Publisher: This article contains the abstract only.

Quantum Information Processing

2001 ◽  
Author(s):  
David P. DiVincenzo ◽  
Charles H. Bennett
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Information Processing
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