Fast and simple scheme for generating NOON states of photons in circuit QED

Abstract

The generation, manipulation and fundamental understanding of entanglement lies at very heart of quantum mechanics. Among various types of entangled states, the NOON states are a kind of special quantum entangled states with two orthogonal component states in maximal superposition, which have a wide range of potential applications in quantum communication and quantum information processing. Here, we propose a fast and simple scheme for generating NOON states of photons in two superconducting resonators by using a single superconducting transmon qutrit. Because only one superconducting qutrit and two resonators are used, the experimental setup for this scheme is much simplified when compared with the previous proposals requiring a setup of two superconducting qutrits and three cavities. In addition, this scheme is easier and faster to implement than the previous proposals, which require using a complex microwave pulse, or a small pulse Rabi frequency in order to avoid nonresonant transitions.

Generating NOON states in circuit QED using a multiphoton resonance in the presence of counter-rotating interactions

“…where ω eg is the pulse frequency, −π/2 is a timeindependent phase and τ ≡ π/(2Ω eg ) is the duration time of the pulse [20]. Here and below, we assume that Rabi frequency Ω eg ≫ |g ef f (n)| (Note g ef f (0) = g ef f ), so that ideally the system evolution due to the qutrit-mode-a interaction is negligible during τ .…”

“…(36) The results (29) and (35) show that the two resonators a and b are eventually prepared in a NOON state. During the state preparation, the whole system is not only subject to the external decoherence channels for each constituent described by the master equation (20), but also under the influence of intrinsic disturbance, such as the crosstalk between the two resonators a and b [47]. Namely, the interaction Hamiltonian V in Eq.…”

“…The protocol in Ref. [20] adopts a setup consisting of one superconducting trans- * Email address: jingjun@zju.edu.cn mon qutrit and two resonators, which demands 2N operations to generate a NOON state with N photons. It has been shortly improved by Ref.…”

Comparison of semiclassical and quantum models of a two-level atom-cavity QED system in the strong coupling regime

“…Recently, there has been novel trends in cavity QED research including, use of solid state photonic cavities with artificial atoms, such quantum dots in micro-pillar or micro-cavity resonators [26]; and circuit QED [28,29,30,31], which uses a superconducting cavity coupled to charge and flux qubits, transmons, fluxoniums, quantum dots and other atom-like entities [31,32,33,34,35,36]. Yet another novel and promising variant of cavity QED in the optical domain which utilizes a fiber waveguide as resonator has recently been developed to generate entangled photons for quantum information processing [37,38,39,40,41,42,43,44,45].…”

Entangling two oscillators with arbitrary asymmetric initial states

“…Recently, hybrid entanglement between particlelike and wave-like optical qubits or between quantum and classical states of light [18,19] has also been demonstrated in experiments, which has drawn increasing attention because hybrid entanglement of light is a key resource in establishing hybrid quantum networks and connecting quantum processors with different encoding qubits. Moreover, a large number of theoretical proposals have been presented for generating particular types of entangled states of light or photons in various physical systems [20][21][22][23][24][25][26][27][28][29][30][31][32][33].…”