Out-of-equilibrium charge dynamics in a hybrid circuit quantum electrodynamics architecture

Viennot, Jeremie; Delbecq, Matthieu; Dartiailh, Matthieu; Cottet, Audrey; Kontos, Takis

doi:10.1103/physrevb.89.165404

Cited by 78 publications

(145 citation statements)

References 29 publications

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“…Here an applied transport voltage drives a current through a double dot, where the energy difference between left and right dot can be used to create photons. The correlation of photon emission and transport properties has been extensively studied [20][21][22][23]. It has also been theoretically shown that lasing can be achieved [20,24].…”

Section: Introductionmentioning

confidence: 99%

Lasing in circuit quantum electrodynamics with strong noise

2015

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We study a model which can describe a superconducting single-electron transistor or a double quantum dot coupled to a transmission-line oscillator. In both cases the degree of freedom is given by a charged particle, which couples strongly to the electromagnetic environment or phonons. We consider the case where a lasing condition is established and study the dependence of the average photon number in the resonator on the spectral function of the electromagnetic environment. We focus on three important cases: a strongly coupled environment with a small cutoff frequency, a structured environment peaked at a specific frequency, and 1/f noise. We find that the electromagnetic environment can have a substantial impact on the photon creation. Resonance peaks are in general broadened and additional resonances can appear.

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Section: Introductionmentioning

confidence: 99%

Lasing in circuit quantum electrodynamics with strong noise

2015

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“…Our model might also find applications in several other fields, such as nanowires [83], carbon nanotubes [84] or quantum dot arrays [85,86]. In particular, pairs of quantum dots have recently been coupled to microwave cavities [29][30][31]. Possible extensions of our model include coupling to multiple transmission channels in different geometries, as well as the competition between light-matter coupling and Anderson localization in random lattices.…”

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confidence: 99%

“…PACS numbers: 05.60. Gg, 42.50.Pq, 74.40.Gh, The study of strong light-matter interactions [1][2][3][4] is playing an increasingly crucial role in understanding as well as engineering new states of matter with relevance to the fields of quantum optics [5][6][7][8][9][10][11][12][13][14][15][16][17][18], solid state physics [19][20][21][22][23][24][25][26][27][28][29][30][31], as well as quantum chemistry [32][33][34][35][36] and material science [37][38][39][40][41][42][43][44][45][46][47][48][49][...…”

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confidence: 99%

Cavity-Enhanced Transport of Charge

et al. 2017

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We theoretically investigate charge transport through electronic bands of a mesoscopic onedimensional system, where inter-band transitions are coupled to a confined cavity mode, initially prepared close to its vacuum. This coupling leads to light-matter hybridization where the dressed fermionic bands interact via absorption and emission of dressed cavity-photons. Using a selfconsistent non-equilibrium Green's function method, we compute electronic transmissions and cavity photon spectra and demonstrate how light-matter coupling can lead to an enhancement of charge conductivity in the steady-state. We find that depending on cavity loss rate, electronic bandwidth, and coupling strength, the dynamics involves either an individual or a collective response of Bloch states, and explain how this affects the current enhancement. We show that the charge conductivity enhancement can reach orders of magnitudes under experimentally relevant conditions. PACS numbers: 05.60. Gg, 42.50.Pq, 74.40.Gh, The study of strong light-matter interactions [1][2][3][4] is playing an increasingly crucial role in understanding as well as engineering new states of matter with relevance to the fields of quantum optics [5][6][7][8][9][10][11][12][13][14][15][16][17][18], solid state physics [19][20][21][22][23][24][25][26][27][28][29][30][31], as well as quantum chemistry [32][33][34][35][36] and material science [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53]. An emerging topic of interest is the modification of material properties using either external electro-magnetic radiation [54][55][56] or spatially confined modes such as in cavity quantum electrodynamics [57][58][59][60][61][62][63]. Recent experiments with organic semiconductors have demonstrated a dramatic enhancement of charge conductivity when molecules interact strongly with a surface plasmon mode [64]. In principle, this can open up exciting new opportunities both for basic science and applications of organic electronics [65]. The microscopic mechanisms leading to charge conductivity enhancement, however, remain today largely unexplained. In this work, we propose a proof-of-principle model that sheds light on the physical mechanisms behind current enhancement due to the interaction with a confined bosonic mode. We show that our model can lead to a dramatic current enhancement by orders of magnitude for certain conditions that can be relevant to typical experiments across fields.The setup we consider [see Fig. 1(a)] consists of a mesoscopic chain of N sites with two orbitals of energy ω 1 and ω 2 ( = 1) in a 1D geometry, forming two bands in a tight-binding picture. The edges of the chain are connected to a source and a drain with a bias voltage across, respectively inserting and removing (spin-less) electrons in the two orbitals at rates Γ 1 and Γ 2 . The on-site interband transitions with energy ω 21 = ω 2 −ω 1 are resonantly coupled to a cavity mode with coupling strength g and loss rate κ. Initially, we only allow electrons in the upper band to hop with a ...

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“…Although the energy splitting due to different spin and valley occupation cannot be resolved by transport measurements, the energy dispersion of the DQD can definitely be changed by the spin and valley coupling [16]. Because the charge noise is very sensitive to the microscopic details of the energy spectrum, such as the bias dependence of the energy levels, the dephasing rate, given by d 2 Ω d 2 | =0 σ (Here σ is the noise term) [4,37] can vary periodically as the spin and valley quantum numbers are periodically altered.…”

mentioning

confidence: 99%

“…For example, many experimental studies have recently been performed to study the interaction between quantum dots (QDs) and resonators, in gate-defined carbon-nanotubes [2][3][4], GaAs [5,6] and InAs nanowire [7,8] structures. Such studies are motivated by considering QDs as promising candidates for quantum information processing.…”

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confidence: 99%

Charge Number Dependence of the Dephasing Rates of a Graphene Double Quantum Dot in a Circuit QED Architecture

et al. 2015

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We use an on-chip superconducting resonator as a sensitive meter to probe the properties of graphene double quantum dots (DQDs) at microwave frequencies. Specifically, we investigate the charge dephasing rates in a circuit quantum electrodynamics (cQED) architecture. The dephasing rates strongly depend on the number of charges in the dots, and the variation has a period of four charges, over an extended range of charge numbers. Although the exact mechanism of this four-fold periodicity in dephasing rates is an open problem, our observations hint at the four-fold degeneracy expected in graphene from its spin and valley degrees of freedom.In recent years, on-chip microwave resonators have emerged as a useful tool both for coupling distant qubits and for sensitive metrology [1]. For example, many experimental studies have recently been performed to study the interaction between quantum dots (QDs) and resonators, in gate-defined carbon-nanotubes [2-4], GaAs [5,6] and InAs nanowire [7,8] structures. Such studies are motivated by considering QDs as promising candidates for quantum information processing. Graphene has also attracted considerable attention in recent years because of its interesting physical properties and potential applications [9]. Like semiconductors, graphene-based QDs have been proposed as potential quantum bits [10]. Various experiments are now underway to study the coherence properties of graphene QDs. For example, using pulsed-gate transient spectroscopy, Volk et al.[11] measured a charge relaxation time of 100 ns in a graphene QD device. However, the dephasing times of grapheme QDs, which benchmark their quantum coherence and may be significantly shorter than their relaxation times, have not yet been measured. In addition, graphene has both spin and valley degrees of freedom, similar to carbon nanotubes [12,13] and Si-based QDs [14]. Spin qubits formed by graphene QDs have been theoretically studied [10], and various valley-related phenomena such as shell filling in carbon nanotubes [12] and valley splitting in silicon [15] have been explored. However, there are no experimental reports on the effects of the four-fold degeneracy caused by the spin and valley degrees in graphene devices.Here, we present an experimental study of a graphene DQD device, which can be considered as a charge qubit that contains a large number of well-defined charge * Corresponding author: gpguo@ustc.edu.cn states. Using the sensitive dispersive readout of a microwave resonator, we measured the charge-state dephasing rates of this DQD in an integrated grapheneresonator device. Applying a quantum model describing the hybrid system, we simultaneously extracted: the DQD-resonator coupling strength, the tunneling rate between each quantum dot, and the charge-state dephasing rates. This microwave spectroscopy overcomes the difficulties of conventional transport techniques and allows us to study DQD dynamics in a large parameter space. In these experiments, we found that the dephasing rates depend on the number of charges in t...

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Out-of-equilibrium charge dynamics in a hybrid circuit quantum electrodynamics architecture

Abstract: International audienc

Cited by 78 publications

References 29 publications

Lasing in circuit quantum electrodynamics with strong noise

Lasing in circuit quantum electrodynamics with strong noise

Cavity-Enhanced Transport of Charge

Charge Number Dependence of the Dephasing Rates of a Graphene Double Quantum Dot in a Circuit QED Architecture

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