Decoherence and relaxation of a qubit coupled to an Ohmic bath directly and via an intermediate harmonic oscillator

Liang, Xian-Ting

doi:10.1016/j.cplett.2007.10.074

Cited by 9 publications

(12 citation statements)

References 35 publications

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“…(12) can be split in a single boson mode with frequency ω r , coupled to a bath characterized by a dissipation rate γ r , i.e. the width of |g(ω)| 2 [43][44][45][46]. Physically, the ω r -mode is the single resonator mode.…”

Section: The Jc-model: Plasmonic Qedmentioning

confidence: 99%

Weak and strong coupling regimes in plasmonic QED

et al. 2013

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We present a quantum theory for the interaction of a two level emitter with surface plasmon polaritons confined in single-mode waveguide resonators. Based on the Green's function approach, we develop the conditions for the weak and strong coupling regimes by taking into account the sources of dissipation and decoherence: radiative and non-radiative decays, internal loss processes in the emitter, as well as propagation and leakage losses of the plasmons in the resonator. The theory is supported by numerical calculations for several quantum emitters, GaAs and CdSe quantum dots and NV centers together with different types of resonators constructed of hybrid, cylindrical or wedge waveguides. We further study the role of temperature and resonator length. Assuming realistic leakage rates, we find the existence of an optimal length at which strong coupling is possible. Our calculations show that the strong coupling regime in plasmonic resonators is accessible within current technology when working at very low temperatures ( 4K). In the weak coupling regime our theory accounts for recent experimental results. By further optimization we find highly enhanced spontaneous emission with Purcell factors over 1000 at room temperature for NV-centers. We finally discuss more applications for quantum nonlinear optics and plasmon-plasmon interactions.

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Section: The Jc-model: Plasmonic Qedmentioning

confidence: 99%

Weak and strong coupling regimes in plasmonic QED

et al. 2013

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“…Since the spectral poses challenge to many existing method, it arouse much attention recently. Till now, it has been studied by many different methods including the quasi-adiabatic propagator path integral (QUAPI) [22,27,28], the Van Vleck perturbation theory together with a Born-Markov master equation [29], the flow equation renormalization [30,31,32], the non-interacting blip approximation (NIBA) [31,33], and generalized polaron transformation method [34,35,36]. Again, most of the works have not considered the effect of temperature.…”

Section: Nd Model: Qubit Coupled To a Dhomentioning

confidence: 99%

Effect of bath temperature on the quantum decoherence

Huang¹,

Zheng²

2010

Chemical Physics Letters

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The dynamics of a qubit in two different environments are investigated theoretically. The first environment is a two level system coupled to a bosonic bath. And the second one is a damped harmonic oscillator. Based on a unitary transformation, we find that the decoherence of the qubit can be reduced with increasing temperature $T$ in the first case, which agree with the results in [Phys. Rev. Lett. 100, 120401], whereas, it can not be reduced with $T$ in the second case. In both cases, the qubit dynamics are changed substantially as the coupling increases or finite detuning appears.Comment: 10 pages, 5 figure

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“…As Makri [26,27] addressed that the method is non-Markovian and it can make the calculations accurate enough even at very low temperatures, large tunneling amplitude and strong couplings for which the Markovian approximation is unsuitable. In paper I [28] using the ITM algorithm we investigated the dynamics and then the decoherence and relaxation of the qubit in the SB and SIB models as the bath modes with higher frequencies than the oscillating frequency of the IHO. In this paper by using the same ITM algorithm we shall investigate the decoherence and relaxation of the qubit in low-and medium-frequency baths.…”

Section: Introductionmentioning

confidence: 99%

Decoherence and relaxation of qubits coupled to low- and medium-frequency Ohmic baths directly and via a harmonic oscillator

Liang

2008

Chemical Physics

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Using the numerical path integral method we investigate the decoherence and relaxation of qubits in spin-boson (SB) and spin-intermediate harmonic oscillator (IHO)-bath (SIB) models. The cases that the environment baths with low and medium frequencies are investigated. It is shown that the qubits in SB and SIB models have the same decoherence and relaxation as the baths with low frequencies. However, the qubits in the two models have different decoherence and relaxation as the baths with medium frequencies. The decoherence and relaxation of the qubit in SIB model can be modulated through changing the coupling coefficients of the qubit-IHO and IHO-bath and the oscillation frequency of the IHO.

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Decoherence and relaxation of a qubit coupled to an Ohmic bath directly and via an intermediate harmonic oscillator

Cited by 9 publications

References 35 publications

Weak and strong coupling regimes in plasmonic QED

Weak and strong coupling regimes in plasmonic QED

Effect of bath temperature on the quantum decoherence

Decoherence and relaxation of qubits coupled to low- and medium-frequency Ohmic baths directly and via a harmonic oscillator

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