We discuss thermal transport through a Josephson junction in a time-dependent situation. We write the spectral representation of the heat current pumped by a generic drive. This enables separation of the dissipative and reactive contributions, of which the latter does not contribute to long-time averages. We discuss the physical interpretation,...
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2017 (v1)PublicationUploaded on: April 14, 2023
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2008 (v1)Publication
It is of high interest, in the context of adiabatic quantum computation, to better understand the complex dynamics of a quantum system subject to a time-dependent Hamiltonian, when driven across a quantum phase transition. We present here such a study in the Lipkin-Meshkov-Glick (LMG) model with one variable parameter. We first display...
Uploaded on: April 14, 2023 -
2018 (v1)Publication
We propose a single-photon detector based on a superconducting quantum interference device (SQUID) with superconductor-normal-metal-superconductor Josephson weak links. One of the two Josephson junctions is connected to an antenna, and is heated when a photon is absorbed. The increase of the weak-link temperature exponentially suppresses the...
Uploaded on: April 14, 2023 -
2013 (v1)Publication
We analyze work done on a quantum system driven by a control field. The average work depends on the whole dynamics of the system, and is obtained as the integral of the average power operator. As a specific example we focus on a superconducting Cooper-pair box forming a two-level system. We obtain expressions for the average work and work...
Uploaded on: April 14, 2023 -
2016 (v1)Publication
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Uploaded on: March 27, 2023 -
2015 (v1)Publication
We propose an approach to define and measure the statistics of work, internal energy and dissipated heat in a driven quantum system. In our framework the presence of a physical detector arises naturally and work and its statistics can be investigated in the most general case. In particular, we show that the quantum coherence of the initial...
Uploaded on: April 14, 2023 -
2010 (v1)Publication
We study the effect of Markovian environmental noise on the dynamics of a two-level quantum system which is steered adiabatically by an external driving field. We express the master equation taking consistently into account all the contributions to the lowest nonvanishing order in the coupling to the Markovian environment. We study the master...
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2012 (v1)Publication
We study the effect of flux noise on the Cooper pair current of a superconducting charge pump. We generalize the definition of the current in order to take into account the contribution induced by the environment. It turns out that this dissipative current vanishes for charge noise but it is finite in general for noise operators that do not...
Uploaded on: March 27, 2023 -
2012 (v1)Publication
We demonstrate controlled pumping of Cooper pairs down to the level of a single pair per cycle, using an rf-driven Cooper-pair sluice. We also investigate the breakdown of the adiabatic dynamics in two different ways. By transferring many Cooper pairs at a time, we observe a crossover between pure Cooper-pair and mixed Cooper-pair-quasiparticle...
Uploaded on: March 27, 2023 -
2013 (v1)Publication
We propose a calorimetric measurement of work in a quantum system. As a physical realization, we consider a superconducting two-level system, a Cooper-pair box, driven by a gate voltage past an avoided level crossing at charge degeneracy. We demonstrate that, with realistic experimental parameters, the temperature measurement of a resistor...
Uploaded on: April 14, 2023 -
2010 (v1)Publication
We present a superconducting circuit in which non-Abelian geometric transformations can be realized using an adiabatic parameter cycle. In contrast to previous proposals, we employ quantum evolution in the ground state. We propose an experiment in which the transition from non-Abelian to Abelian cycles can be observed by measuring the pumped...
Uploaded on: March 27, 2023 -
2017 (v1)Publication
Two superconductors coupled by a weak link support an equilibrium Josephson electrical current that depends on the phase difference ϕ between the superconducting condensates. Yet, when a temperature gradient is imposed across the junction, the Josephson effect manifests itself through a coherent component of the heat current that flows opposite...
Uploaded on: April 14, 2023 -
2010 (v1)Publication
One of the challenges of adiabatic control theory is the proper inclusion of the effects of dissipation. Here we study the adiabatic dynamics of an open two-level quantum system deriving a generalized master equation to consistently account for the combined action of the driving and dissipation. We demonstrate that in the zero-temperature limit...
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2019 (v1)Publication
We suggest a single-photon thermal detector based on the abrupt jump of the critical current of a temperature-biased tunnel Josephson junction formed by different superconductors, working in the dissipationless regime. The electrode with the lower critical temperature is used as a radiation-sensing element, so it is thermally floating and is...
Uploaded on: March 27, 2023 -
2013 (v1)Publication
We show that the dynamics of a driven quantum system weakly coupled to the environment can exhibit two distinct regimes. While the relaxation basis is usually determined by the system + drive Hamiltonian (system-governed dynamics), we find that under certain conditions it is determined by specific features of the environment, such as, the form...
Uploaded on: April 14, 2023 -
2011 (v1)Publication
Motivated by recent experiments on quantum mechanical charge pumping in a Cooper pair sluice, we present a measurement scheme for observing shifts of transition frequencies in two-level quantum systems induced by broadband environmental fluctuations. In contrast to quantum optical and related setups based on cavities, the impact of a thermal...
Uploaded on: March 27, 2023 -
2014 (v1)Publication
As quantum systems become more experimentally accessible, we are forced to reconsider the notions of control and work to fully account for quantum effects. To this end, we identify the work injected into a quantum system during a general quantum-mechanical driving protocol and quantify the relevant heat flows. The known results that are...
Uploaded on: April 14, 2023 -
2021 (v1)Publication
Since the 1960s a deep and surprising connection has followed the development of superconductivity and quantum field theory. The Anderson-Higgs mechanism and the similarities between the Dirac and Bogoliubov-de Gennes equations are the most intriguing examples. In this last analogy, the massive Dirac particle is identified with a quasiparticle...
Uploaded on: April 14, 2023 -
2016 (v1)Publication
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Uploaded on: April 14, 2023