Bright On-Demand Source of Antibunched Microwave Photons Based on Inelastic Cooper Pair Tunneling

Abstract

The ability to generate single photons is not only an ubiquitous tool for scientific exploration with applications ranging from spectroscopy and metrology 1,2 to quantum computing 3 , but also an important proof of the underlying quantum nature of a physical process 4 . In the microwave regime, emission of anti-bunched radiation has so far relied on coherent control of Josephson qubits 5-8 , where precisely calibrated microwave pulses are needed, and the achievable bandwidth is limited by the anharmonicity of the qubit. Here, we demonstrate the operation of a bright on-demand source of quantum microwave radiation capable of emitting anti-bunched photons based on inelastic Cooper pair tunneling and driven by a simple DC voltage bias. It is characterized by its normalized second order correlation function of g (2) (0) ≈ 0.43 corresponding to anti-bunching in the single photon regime. Our source can be triggered and its emission rate is tunable in situ exceeding rates obtained with current microwave single photon sources by more than one order of magnitude.

Absence of a Dissipative Quantum Phase Transition in Josephson Junctions

“…This is clearly not the case in our experiments. In a totally independent experiment with a different objective, Grimm and co-workers [27] have recently observed that a Josephson junction with E J /E C 0.3 in series with a 32 kΩ resistance (R Q /R 0.2) allows a supercurrent flow. We consider their observation backs our results.…”

Single-Photon Emission Mediated by Single-Electron Tunneling in Plasmonic Nanojunctions

“…For voltages eV L = −eV R ≤ 2ω c [44] we have 12 ]+κ ↓ (2κ ↓ + Γ 02 ), and the rate Γ 12 = e −λ 2 λ 2 2 − λ 2 2 α Γ α n F (ω c −µ α )/2 for the transition from 1 to 2 photons in the cavity. Equation (4) agrees very well with the numerical calculations for k B T ≥ 0.1ω c , (cf.…”

Josephson photonics with simultaneous resonances

“…Circuits in which voltage biased Josephson junctions (JJ) are combined with microwave cavities provide an ideal platform for exploring a wide range of microwave photonics. All of the voltage energy associated with tunneling Cooper pairs must be transferred into photons and the properties of JJ-cavity systems can be tuned over a wide range either in-situ or by design, [1][2][3][4][5][6] . Furthermore, the energy transferred by tunneling Cooper pairs into microwave modes can be tracked by monitoring either the resulting dc current or the microwaves leaking out of the circuit 1 .…”

“…Furthermore, the energy transferred by tunneling Cooper pairs into microwave modes can be tracked by monitoring either the resulting dc current or the microwaves leaking out of the circuit 1 . Recent experimental, [1][2][3][4][5][6] and theoretical work [7][8][9][10][11][12][13][14][15][16][17][18] has explored a wide range of ways in which JJ-cavity systems can be used to generate non-classical microwave states.…”