Environment-Mediated Control of a Quantum System

Romano, Raffaele; D’Alessandro, Domenico

doi:10.1103/physrevlett.97.080402

Cited by 56 publications

(50 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We demonstrate that the equilibrium solubility of dopants need not be monotonic in x and lie between those of the pure materials A and B. Instead, we will show that careful tuning of x can result in equilibrium solubilities many orders of magnitude higher in the alloy than in either of the pure materials.It is well known that high doping can alter the lattice constant of a material [14]. Here we investigate the possibility of using changes in the lattice constant to control the doping concentration.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Increasing the Equilibrium Solubility of Dopants in Semiconductor Multilayers and Alloys

et al. 2008

View full text Add to dashboard Cite

We have theoretically studied the possibility to control the equilibrium solubility of dopants in semiconductor alloys, by strategic tuning of the alloy concentration. From the modeled cases of C 0 in Si x Ge 1ÿx , Zn ÿ and Cd ÿ in Ga x In 1ÿx P it is seen that under certain conditions the dopant solubility can be orders of magnitude higher in an alloy or multilayer than in either of the elements of the alloy. This is found to be due to the solubility's strong dependence on the lattice constant for size mismatched dopants. The equilibrium doping concentration in alloys or multilayers could therefore be increased significantly. More specifically, Zn ÿ in a Ga x In 1ÿx P multilayer is found to have a maximum solubility for x 0:9, which is 5 orders of magnitude larger than that of pure InP. [8][9][10]. From a theoretical point of view the raised nonequilibrium concentrations have been successfully explained by the increased range of the chemical potential of the dopant during epitaxial growth [11][12][13].In this Letter we consider ways to increase the solid solubility to achieve higher doping concentrations under equilibrium conditions. We study the dependence of the equilibrium solubility of substitutional defects, including dopants, in compound semiconductors A x B 1ÿx . We demonstrate that the equilibrium solubility of dopants need not be monotonic in x and lie between those of the pure materials A and B. Instead, we will show that careful tuning of x can result in equilibrium solubilities many orders of magnitude higher in the alloy than in either of the pure materials.It is well known that high doping can alter the lattice constant of a material [14]. Here we investigate the possibility of using changes in the lattice constant to control the doping concentration. Initial indications of this have been noted in previous experimental work [15], in theoretical studies of dopants in silicon under applied biaxial strain [16] and for vacancies and self-interstitials using a phenomenological method [17]. However, the full implications of this possibility have not so far been realized.Our hypothesis builds on the way in which the solubility depends on the difference between the dopant's and the substituted host atom's equilibrium bond lengths. The solubility of a dopant atom of the same size and equilibrium bonding distance as the host atoms will have little dependence on the strain of the material since the difference in bond energy will be constant. If the equilibrium bonding distances differ, however, the solubility of the dopant may have a strong dependence on the lattice constant, such that the equilibrium solubility of smaller (larger) dopants increases under compressive (expansive) strain. Our results show for the first time that the equilibrium concentration of a defect can sometimes be orders of magnitude higher in an alloy or multilayer than in either of the constituents. This leads to the possibility of increasing the equilibrium solubilities of dopants through strategically composing multilayers or alloys...

show abstract

mentioning

confidence: 99%

“…It is well known that high doping can alter the lattice constant of a material [14]. Here we investigate the possibility of using changes in the lattice constant to control the doping concentration.…”

mentioning

confidence: 99%

Increasing the Equilibrium Solubility of Dopants in Semiconductor Multilayers and Alloys

et al. 2008

View full text Add to dashboard Cite

show abstract

“…The idea of indirect control using projective measurements [13], completely-controlled dynamics [14,15], or initializations [16] of an ancillary system has been studied theoretically and has applications in hybrid systems composed of electron spins and nuclear spins [17][18][19][20][21]. If those frequent operations performed on the actuator subsystem are unitary rather than noisy, both subsystems can evolve independently and coherently, which is known as the dynamical decoupling [22].…”

Section: Introductionmentioning

confidence: 99%

Quantum computation with noisy operations

Liu

2015

Phys. Rev. A

View full text Add to dashboard Cite

In this paper, we show how to use low-fidelity operations to control the dynamics of quantum systems. Noisy operations usually drive a system to evolve into a mixed state and damage the coherence. Sometimes frequent noisy operations result in the coherent evolution of a subsystem, and the dynamics of the subsystem is controlled by tuning noisy operations. Based on this, we find that universal quantum computation can be carried out by low-fidelity (fidelity < 90%) operations.

show abstract

“…[1][2][3][4][5] Decoherence is usually a limitation for quantum control, 6 but recent technological advances have increased tremendously the coherence time up to several seconds for electron-spin 7 or minutes in the case of some nuclear-spin. 8 Moreover, there are also decoherent quantum control strategies, where coherence is destroyed in order to improve the controllability of the system, [9][10][11] this allows to achieve states that cannot be accessed by unitary evolution. Measurement, manipulation, and computation of quantum information can be counted among some of the most important goals of quantum control.…”

Section: Introductionmentioning

confidence: 99%

Quantum control of isomerization by robust navigation in the energy spectrum

Murgida

Arranz

Borondo

2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

In this paper, we present a detailed study on the application of the quantum control technique of navigation in the energy spectrum to chemical isomerization processes, namely, CN-Li Li-CN. This technique is based on the controlled time variation of a Hamiltonian parameter, an external uniform electric field in our case. The main result of our work establishes that the navigation involved in the method is robust, in the sense that quite sizable deviations from a pre-established control parameter time profile can be introduced and still get good final results. This is specially relevant thinking of a experimental implementation of the method. C 2015 AIP Publishing LLC. [http://dx

show abstract

Environment-Mediated Control of a Quantum System

Cited by 56 publications

References 22 publications

Increasing the Equilibrium Solubility of Dopants in Semiconductor Multilayers and Alloys

Increasing the Equilibrium Solubility of Dopants in Semiconductor Multilayers and Alloys

Quantum computation with noisy operations

Quantum control of isomerization by robust navigation in the energy spectrum

Contact Info

Product

Resources

About