Current rectification in a single molecule diode: the role of electrode coupling

Sherif, Siya; Rubio‐Bollinger, Gabino; Pinilla-Cienfuegos, Elena; Coronado, Eugenio; Cuevas, Juan Carlos; Agraı̈t, Nicolás

doi:10.1088/0957-4484/26/29/291001

Cited by 54 publications

(51 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results [21] confirm that all transitions between different spin states of GdW 30 are in good speaking terms with these circuits. Besides, its molecular character ensures that they can be taken out of the crystal and placed individually on a surface or in a device [28].…”

Section: The Resulting Coordination Around Gdmentioning

confidence: 99%

Coherent manipulation of three-qubit states in a molecular single-ion magnet

et al. 2017

View full text Add to dashboard Cite

We show that several qubits can be integrated in a single magnetic ion, using its internal electronic spin states with energies tuned by a suitably chosen molecular environment. This approach is illustrated with a nearly-isotropic Gd 3+ ion entrapped in a polyoxometalate molecule. Experiments with microwave technologies, either three dimensional cavities or quantum superconducting circuits, show that this magnetic molecule possesses the number of spin states and the set of coherently addressable transitions connecting these states that are needed to perform a universal three-qubit processor or, equivalently, a d = 8-level 'qudit'. Our findings open prospects for developing more sophisticated magnetic molecules which can result in more powerful and noise resilient quantum computation schemes.PACS numbers: 75.50. Xx,03.67.Lx,75.45.+j,75.30.Gw Molecular nanomagnets have emerged in the last few years as promising candidates to realize qubits, the basic components of future quantum computers [1][2][3][4]. These artificial molecules, designed and synthesized by chemical methods, consist of a magnetic core surrounded by nonmagnetic ligands. They are perfectly monodisperse and remain stable in different material forms, from perfectly ordered crystals to solutions and, in some cases, also when they are deposited onto solid substrates [5]. The main sources of magnetic noise, which introduce decoherence, arise from hyperfine couplings to nuclear spins and from dipolar couplings to other electronic spins in their neighborhood [6,7]. These effects can be minimized by isotopical purification and by extreme dilution in a diamagnetic matrix or in appropriate solvents. This strategy has recently led to spin coherence times [3,8,9] comparable to those reported for other solid-state spin qubit systems, such as NV centres in diamond and P donors in silicon [10,11]. An alternative is to identify the qubit states with clock transitions, which are relatively insensitive to magnetic field fluctuations [12]. However, even if the qubit-qubit interactions are minimized these strategies offer no route to scalability. This paradox between coupling and isolation has severely limited progressing beyond the realization of elemental two-qubit gates with electronic spins [13][14][15].Here, we explore a different approach: to have multiple qubits coupled in a single atom. Systems having d = 2 N internal levels (or 'qudits') can in principle realize N qubits. Lanthanide ions are promising candidates to realize these systems since the multiplet associated with the angular momentum J, given by Hund's rules, defines (2J + 1) states. Its practical implementation is not straightforward, though, because the level splitting induced by the crystal field around the lanthanide is often so large that only the two lowest lying electronic levels are experimentally accessible [12,16,17]. Nuclear spin states might still allow the definition of several qubits in lanthanides with a nonzero I [16,18]. However, the transitions that connect these states have very ...

show abstract

Section: The Resulting Coordination Around Gdmentioning

confidence: 99%

Coherent manipulation of three-qubit states in a molecular single-ion magnet

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Rectification has been studied in a variety of junction setups since the early days of molecular electronics 50,51 . Recent experiments and supporting computational investigations have demonstrated that one can achieve robust molecular diodes with rectification ratios of two and even three orders of magnitude in SAMs 52 and single molecules 53,54 . The mechanism of rectification in many proposed molecular structures is based on the assumption of coherent tunneling, more precisely, on the fact that deep-tunneling conductance is orders of magnitude smaller than resonant transmission, see for example 55,56 .…”

Section: Introductionmentioning

confidence: 94%

“…The commonly examined "tunneling diode" relies on the dramatic contrast between deep tunneling conductance and ballistic transport, see for example recent experiments 52,54 and theoretical studies 55,56 . In these systems, rectification arises e.g.…”

Section: Environmentally Induced Diodesmentioning

confidence: 99%

Inelastic effects in molecular transport junctions: The probe technique at high bias

Kilgour

Segal

2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

We extend the Landauer-Büttiker probe formalism for conductances to the high bias regime, and study the effects of environmentally-induced elastic and inelastic scattering on charge current in single molecule junctions, focusing on high-bias effects. The probe technique phenomenologically incorporates incoherent elastic and inelastic effects to the fully coherent case, mimicking a rich physical environment at trivial cost. We further identify environmentally-induced mechanisms which generate an asymmetry in the current, manifested as a weak diode behavior. This rectifying behavior, found in two types of molecular junction models, is absent in the coherent-elastic limit, and is only active in the case with incoherent-inelastic scattering. Our work illustrates that in the low bias -linear response regime, the commonly used "dephasing probe" (mimicking only elastic decoherence effects) operates nearly indistinguishably from a "voltage probe" (admitting inelasticdissipative effects). However, these probes realize fundamentally distinct I-V characteristics at high biases, reflecting the central roles of dissipation and inelastic scattering processes on molecular electronic transport far-from-equilibrium.

show abstract

“…17 Among polyoxometalates, a most promising family would be the single ion magnets and molecular spin qubits LnW30 18,19 and in particular TbW30 which has experimentally be proven to function as a single-molecule rectifier. 20 We chose not to start our theoretical study with these promising families purely because of reasons of computational cost: Lanthanoid complexes need an explicit consideration of the spin-orbit coupling with relativistic pseudopotentials that would make the initial exploration much more challenging. In addition, except for some organometallic 'sandwiches', all the lanthanoid single ion magnets present a larger number of atoms per molecule compared with other simpler families.…”

Section: : Detailed Comments On the Selection Of Molecules For The Ementioning

confidence: 99%

Theoretical Evaluation of [V^IV(α-C₃S₅)₃]^2– as Nuclear-Spin-Sensitive Single-Molecule Spin Transistor

Cardona‐Serra

Gaita‐Ariño

Stamenova

et al. 2017

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

In a straightforward application of molecular nanospintronics to quantum computing, single-molecule spin transistors can be used to measure nuclear spin qubits. Conductance jumps accompany electronic spin flips at the so-called anticrossings between energy levels, which take place only at specific magnetic fields determined by the nuclear spin state. To date, the only molecular hardware employed for this technique has been the terbium(III) bis(phthalocyaninato) complex. Here we explore theoretically whether a similar behavior is expected for a highly stable molecular spin qubit, the vanadium tris-dithiolate complex [V(α-CS)]. We consider such a molecule between two gold electrodes and determine the spin-dependent conductance. We verify that the transport channel in experimental conditions does not overlap with the occupied spin orbitals, indicating that the spin states may survive in the conduction regime. We validate the robustness of the theoretical methodology by studying two chemically related vanadium complexes and offer some criteria to guide the experiments.

show abstract

Current rectification in a single molecule diode: the role of electrode coupling

Cited by 54 publications

References 25 publications

Coherent manipulation of three-qubit states in a molecular single-ion magnet

Coherent manipulation of three-qubit states in a molecular single-ion magnet

Inelastic effects in molecular transport junctions: The probe technique at high bias

Theoretical Evaluation of [V^IV(α-C₃S₅)₃]^2– as Nuclear-Spin-Sensitive Single-Molecule Spin Transistor

Contact Info

Product

Resources

About

Current rectification in a single molecule diode: the role of electrode coupling

Cited by 54 publications

References 25 publications

Coherent manipulation of three-qubit states in a molecular single-ion magnet

Coherent manipulation of three-qubit states in a molecular single-ion magnet

Inelastic effects in molecular transport junctions: The probe technique at high bias

Theoretical Evaluation of [VIV(α-C3S5)3]2– as Nuclear-Spin-Sensitive Single-Molecule Spin Transistor

Contact Info

Product

Resources

About

Theoretical Evaluation of [V^IV(α-C₃S₅)₃]^2– as Nuclear-Spin-Sensitive Single-Molecule Spin Transistor