Observation of Atomlike Nitrogen in Nitrogen-Implanted Solid<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">C</mml:mi></mml:mrow><mml:mrow><mml:mn>60</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Murphy, Tony; Pawlik, Th.; Weidinger, A.; Höhne, M.; Alcalá, R.; Spaeth, J.‐M.

doi:10.1103/physrevlett.77.1075

Cited by 385 publications

(90 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…mT in CS 2 [5]. The electron nuclear double resonance (ENDOR) spectrum consists of four principle lines associated with the four M S states, each of which is further split into two by the secondorder hyperfine interaction [6], enabling selective excitation of (for example) the M I = 0 to M I = +1 transition.…”

Section: Methodsmentioning

confidence: 99%

The N@C₆₀ nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates

Morton

Tyryshkin

Ardavan

et al. 2006

Physica Status Solidi (b)

View full text Add to dashboard Cite

Nuclear spins have been proposed for the embodiment of quantum information and yielded the most complex demonstrations of quantum algorithms to date. However, the weak thermal polarisation of nuclear spins in experimentally accessible conditions has presented a barrier to further scaling. Here, we discuss the benefits of a coupled electron spin to the nuclear spin qubit and demonstrate the ideas using the 14 N nuclear spin in the N@C 60 molecule. In addition to providing a resource for nuclear spin polarisation and detection, the electron spin can be exploited to perform ultrafast nuclear spin phase gates, which can in turn be used to dynamically bang-bang decouple the nuclear spin from unwanted interactions.

show abstract

Section: Methodsmentioning

confidence: 99%

The N@C₆₀ nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates

Morton

Tyryshkin

Ardavan

et al. 2006

Physica Status Solidi (b)

View full text Add to dashboard Cite

show abstract

“…1b) [16]. Information on the origin of the 12-level spin system in N@C 60 is provided in the supplementary online material, along with other experimental details.…”

Section: Figmentioning

confidence: 99%

Bang–bang control of fullerene qubits using ultrafast phase gates

et al. 2005

View full text Add to dashboard Cite

Quantum mechanics permits an entity, such as an atom, to exist in a superposition of multiple states simultaneously. Quantum information processing (QIP) harnesses this profound phenomenon to manipulate information in radically new ways [1]. A fundamental challenge in all QIP technologies is the corruption of superposition in a quantum bit (qubit) through interaction with its environment. Quantum bang-bang control provides a solution by repeatedly applying 'kicks' to a qubit [2,3], thus disrupting an environmental interaction. However, the speed and precision required for the kick operations has presented an obstacle to experimental realization. Here we demonstrate a phase gate of unprecedented speed [4, 5] on a nuclear spin qubit in a fullerene molecule, and use it to bang-bang decouple the qubit from a strong environmental interaction. We can thus trap the qubit in closed cycles on the Bloch sphere, or lock it in a given state for an arbitrary period. Our procedure uses operations on a second qubit, an electron spin, in order to generate an arbitrary phase on the nuclear qubit. We anticipate the approach will be vital for QIP technologies, especially at the molecular scale where other strategies, such as electrode switching, are unfeasible.Two well known concepts in overcoming the corruption of information stored within a qubit are decoherence free subspaces [6,7,8,9], and quantum error correcting codes [10,11,12]. The former is the passive solution of restricting oneself to some set of states that, due to symmetries in the system, are largely immune to the dominant types of unwanted coupling. The latter is a sophisticated form of feedback control whereby the effect of unwanted coupling is detected and corrected. Between these limits there is the idea of dynamical suppression of couplingmaking some rapid, low level manipulation of the system so as to actively interfere with the decoherence process. Ideas here often relate to the 'quantum Zeno effect' in which repeated measurement (or some related process) is capable of suppressing the natural evolution of the system [13,14]. As the system evolves from one quantum eigenstate, |0 , to another, |1 , it passes through a * Electronic address: john.morton@materials.ox.ac.uk FIG. 1:A representation of our decoupling scheme, and the physical system to which it is applied. (a) Our decoupling process -shown by the path of the nuclear qubit on its Bloch sphere. The line within the Bloch sphere is a visual guide and does not indicate that the state becomes mixed. The state leaves the two-state space represented by the Bloch sphere, and returns at the indicated point on the opposite side, remaining pure at all times. An RF field is applied to drive state |00 to |01 . However, applying a phase of −1 to |01 during the evolution causes the state to jump to the other side of the Bloch sphere, from which it must evolve back to its initial state. The process can be repeated to prevent the system from ever reaching |01 . (b) A model of the N@C60 molecule. (c) Although this N@C60 ...

show abstract

“…1(A) shows the continuous-wave EPR spectrum of N@C 60 in CS 2 at room temperature. The spectrum is centered on the electron g-factor g = 2.0036 and comprises three lines resulting from the hyperfine coupling to 14 N [9]. The relevant isotropic spin Hamiltonian (in angular frequency units) is:…”

Section: Methodsmentioning

confidence: 99%

A new mechanism for electron spin echo envelope modulation

Morton

Tyryshkin

Ardavan

et al. 2005

The Journal of Chemical Physics

View full text Add to dashboard Cite

Electron spin echo envelope modulation (ESEEM) has been observed for the first time from a coupled hetero-spin pair of electron and nucleus in liquid solution. Previously, modulation effects in spin echo experiments have only been described in liquid solutions for a coupled pair of homonuclear spins in NMR or a pair of resonant electron spins in EPR. We observe low-frequency ESEEM (26 and 52 kHz) due to a new mechanism present for any electron spin with S > 1/2 that is hyperfine coupled to a nuclear spin. In our case these are electron spin (S = 3/2) and nuclear spin (I = 1) in the endohedral fullerene N@C 60 . The modulation is shown to arise from second order effects in the isotropic hyperfine coupling of an electron and 14 N nucleus. * Electronic address: john.morton@materials.ox.ac.uk

show abstract

Observation of Atomlike Nitrogen in Nitrogen-Implanted SolidC60

Cited by 385 publications

References 14 publications

The N@C₆₀ nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates

The N@C₆₀ nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates

Bang–bang control of fullerene qubits using ultrafast phase gates

A new mechanism for electron spin echo envelope modulation

Contact Info

Product

Resources

About

Observation of Atomlike Nitrogen in Nitrogen-Implanted SolidC60

Cited by 385 publications

References 14 publications

The N@C60 nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates

The N@C60 nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates

Bang–bang control of fullerene qubits using ultrafast phase gates

A new mechanism for electron spin echo envelope modulation

Contact Info

Product

Resources

About

The N@C₆₀ nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates

The N@C₆₀ nuclear spin qubit: Bang‐bang decoupling and ultrafast phase gates