|
1
|
Stevens J, Szombati D, Maffei M, Elouard C, Assouly R, Cottet N, Dassonneville R, Ficheux Q, Zeppetzauer S, Bienfait A, Jordan AN, Auffèves A, Huard B. Energetics of a Single Qubit Gate. PHYSICAL REVIEW LETTERS 2022; 129:110601. [PMID: 36154409 DOI: 10.1103/physrevlett.129.110601] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
Qubits are physical, a quantum gate thus not only acts on the information carried by the qubit but also on its energy. What is then the corresponding flow of energy between the qubit and the controller that implements the gate? Here we exploit a superconducting platform to answer this question in the case of a quantum gate realized by a resonant drive field. During the gate, the superconducting qubit becomes entangled with the microwave drive pulse so that there is a quantum superposition between energy flows. We measure the energy change in the drive field conditioned on the outcome of a projective qubit measurement. We demonstrate that the drive's energy change associated with the measurement backaction can exceed by far the energy that can be extracted by the qubit. This can be understood by considering the qubit as a weak measurement apparatus of the driving field.
Collapse
Affiliation(s)
- J Stevens
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - D Szombati
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - M Maffei
- CNRS and Université Grenoble Alpes, Institut Néel, F-38042 Grenoble, France
| | - C Elouard
- QUANTIC team, INRIA de Paris, 2 Rue Simone Iff, 75012 Paris, France
| | - R Assouly
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - N Cottet
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - R Dassonneville
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - Q Ficheux
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - S Zeppetzauer
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - A Bienfait
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - A N Jordan
- Institute for Quantum Studies, Chapman University, 1 University Drive, Orange, California 92866, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - A Auffèves
- CNRS and Université Grenoble Alpes, Institut Néel, F-38042 Grenoble, France
| | - B Huard
- Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| |
Collapse
|
|
2
|
Katamadze KG, Kovlakov EV, Avosopiants GV, Kulik SP. Direct test of the "quantum vampire's" shadow absence with use of thermal light. OPTICS LETTERS 2019; 44:3286-3289. [PMID: 31259941 DOI: 10.1364/ol.44.003286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
The counterintuitive nature of quantum physics leads to a number of paradoxes. One of them is a "quantum vampire" effect [Fedorov et al., Optica2, 112 (2015)OPTIC82334-253610.1364/OPTICA.2.000112], which means that the photon annihilation in a part of a large beam does not change the shape of the beam profile (i.e., does not cast a shadow), but it may change the total beam intensity. Previously, this effect was demonstrated just in a simplified double-mode regime [Fedorov et al., Optica2, 112 (2015), OPTIC82334-253610.1364/OPTICA.2.000112 Katamadze et al., Optica5, 723 (2018)OPTIC82334-253610.1364/OPTICA.5.000723]. In this Letter, a direct test of shadow absence after the photon annihilation was performed using the thermal state of light at the input.
Collapse
|