arXiv:1108.4371 · Physical Review Letters

Coupling a Quantum Dot, Fermionic Leads, and a Microwave Cavity on a Chip

Matthieu R. Delbecq, Vivien Schmitt, François D. Parmentier, Nicolas Roch, J. J. Viennot, Gwendal Fève, Benjamin Huard, Christophe Mora, Audrey Cottet, Takis Kontos

Published Dec 16, 2011• 207 citations

arXiv HTML PDF

Abstract

We demonstrate a hybrid architecture consisting of a quantum dot circuit coupled to a single mode of the electromagnetic field. We use single wall carbon nanotube based circuits inserted in superconducting microwave cavities. By probing the nanotube dot using a dispersive readout in the Coulomb blockade and the Kondo regime, we determine an electron-photon coupling strength which should enable circuit QED experiments with more complex quantum dot circuits.

DOI: 10.1103/physrevlett.107.256804

Related papers

Quantum dot circuits in microwave cavities

M.R. Delbecq L.E. Bruhat J.J. Viennot S. Datta A. Cottet And T. Kontos

We present our recent experiments where we demonstrate a hybrid architecture consisting of a quantum dot circuit coupled to a single mode of the electromagnetic ¯eld. We use single wall carbon nanotube based circuits inserted in superconducting microwave cavities. By probing the nanotube dot using a dispersive readout in the Coulomb blockade and the Kondo regime, we determine an electron-photon coupling strength which should enable circuit QED experiments with more complex quantum dot circuits. We extend our architecture to two quantum dot circuits in a microwave cavity. These circuits are separated by 200 times their own size, but share the same anti-node of the cavity ¯eld. We demonstrate their interaction mediated by the cavity photons.

Jun 1, 20120 citations

Charge and spin dynamics in a hybrid circuit quantum electrodynamics architecture

J. J. Viennot

This thesis investigates experimentally the coupling mechanism of the charge and spin degrees of freedom in double quantum dots to high finesse superconducting microwave cavities. We use carbon nanotubes as a coherent conductor to host our quantum dots.We conceived an experimental setup and developed new fabrication methods in order to achieve control over these devices. With these methods, we scrutinize the resonant coupling of the dot's charge electronic transitions to a microwave cavity. We drive the system out of equilibrium to characterise its dynamics and extract its relevant intrinsic parameters. We examine a possible coupling of single photons to a single electron spin, using non-collinear exchange fields induced from ferromagnetic interfaces as a key ingredient to engineer this coupling. The preliminary results in this circuit architecture are promising for future spin-based QED experiments with single spins.

Jun 6, 20140 citations

Circuit QED with a quantum-dot charge qubit dressed by Cooper pairs

Laure E. Bruhat, Tino Cubaynes, J. J. Viennot +4 more

Coupling double-quantum-dot circuits to microwave cavities provides a powerful means to control, couple, and manipulate qubits based on the charge or spin of individual electrons. Here, we revisit this standard configuration by adding superconductivity to the circuit. We combine theory and experiment to study a superconductor--double-quantum-dot circuit coupled to microwave cavity photons. First, we use the cavity as a spectroscopic probe. This allows us to determine the low-energy spectrum of the device and to reveal directly Cooper-pair-assisted tunneling between the two dots. Second, we observe a vacuum Rabi splitting which is a signature of strong charge photon coupling and a premiere with carbon-nanotube-based quantum-dot circuits. We show that our circuit design intrinsically combines a set of key features to achieve the strong coupling regime to the cavity. A low charging energy reduces the device sensitivity to charge noise, while sufficient coupling is provided by the shaping of the spectrum of the double quantum dot by the superconducting reservoir. Our findings could be adapted to many other circuit designs and shed light on the coupling of superconducting nanoscale devices to microwave fields.

arXiv:1612.05214Physical review. B./Physical review. BOct 18, 201864 citations

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

J. J. Viennot, Matthieu R. Delbecq, Matthieu Dartiailh +2 more

The recent development of hybrid circuit quantum electrodynamics allows one to study how cavity photons interact with a system driven out of equilibrium by fermionic reservoirs. We study here one of the simplest combination: a double quantum dot coupled to a single mode of the electromagnetic field. We are able to couple resonantly the charge levels of a carbon-nanotube-based double dot to cavity photons. We perform a microwave readout of the charge states of this system, which allows us to unveil features of the out-of-equilibrium charge dynamics, otherwise invisible in the DC current. We extract the relaxation rate, dephasing rate, and photon number of the hybrid system using a theory based on a master equation technique. These findings open the path for manipulating other degrees of freedom, e.g., the spin and/or the valley in nanotube-based double dots using microwave light.

arXiv:1310.4363Physical Review BApr 4, 201493 citations

Circuit Quantum Electrodynamics with hybrid quantum dot devices

Audrey Cottet

Coupling on-chip microwave cavities to superconducting microcircuits has provided a new platform to study the light/matter interaction at the most elementary level [1]. Coupling such cavities to more complex quantum circuits, like quantum dot circuits, is of high interest since it would allow the use of different degrees of freedom, like for instance the electronic spin, in a cavity quantum electrodynamics context. In this talk, I will present various theoretical proposals which would exploit this possibility. First, I will present a scheme allowing a strong coupling between cavity photons and a single spin trapped in a double quantum dot with ferromagnetic contacts [2]. Such a scheme would enable a scalable spin quantum bit architecture. Second, I will discuss theoretically the coupling of a double-quantum dot based Cooper pair splitter to a cavity [3]. Such a scheme can be used to test the entanglement of split Cooper pairs, due to a subradiance property of the Cooper pairs singlet state. Third, I will present recent experiments on carbon nanotube based quantum dots coupled to microwave cavities. In particular, I will discuss the observation of a charge coupling between two distant quantum dots mediated by cavity photons. [1] A. Wallraff, D. I. Schuster, A. Blais, L. Frunzio, R.- S. Huang, J. Majer, S. Kumar, S.M. Girvin, and R. J. Schoelkopf, Nature (London) 431, 162 (2004). [2] A. Cottet and T. Kontos, Phys. Rev. Lett. 105, 160502 (2010) [3] A. Cottet, T. Kontos, and A. Levy Yeyati, Phys. Rev. Lett. 108, 166803 (2012). [5] M.R. Delbecq, V. Schmitt, F.D. Parmentier, N. Roch, J.J. Viennot, G. Fève, B. Huard, C. Mora, A. Cottet, and T. Kontos, Phys. Rev. Lett. 107,256804 (2011) [6] M.R. Delbecq et al., unpublished

Nov 7, 20120 citations

Circuit QED with Carbon-Nanotube-Based Superconducting Quantum Circuits

Edward A. Laird

Hybrid circuit quantum electrodynamics (QED) involves the study of coherent quantum physics in solid state systems via their interactions with superconducting microwave circuits.Here we present a crucial step in the implementation of a hybrid superconducting qubit that employs a carbon nanotube as a Josephson junction.We realise the junction by contacting a carbon nanotube with a superconducting Pd/Al bi-layer, and implement voltage tunability of the quantum circuit's frequency using a local electrostatic gate.We demonstrate a strong dispersive coupling to a coplanar waveguide resonator by investigating the gate-tunable resonator frequency.We extract qubit parameters from spectroscopy using dispersive readout and find qubit relaxation and coherence times in the range of 10 -200 ns.

May 21, 20210 citations