43 citations · 209 across the 17 of their papers we have counts for
18 papers
Melting phase diagram of the two-dimensional electron solid in a perpendicular magnetic field
M. Yu. Melnikov, D. G. Smirnov, A. A. Shashkin +3
We determine the thermal melting phase diagram of the electron solid by measuring the onset density of the double-threshold voltage-current curves in the insulating state in the ul…
Inequivalence of the low-density insulating state and quantum Hall insulating states in a strongly correlated two-dimensional electron system
M. Yu. Melnikov, D. G. Smirnov, A. A. Shashkin +3
We find that the behaviors of the voltage-current characteristics as one enters the low-density insulating state and integer quantum Hall insulating states in the ultra-clean two-d…
Stabilization of a two-dimensional quantum electron solid in perpendicular magnetic fields
M. Yu. Melnikov, D. G. Smirnov, A. A. Shashkin +3
We find that the double-threshold voltage-current characteristics in the insulating regime in the ultra-clean two-valley two-dimensional electron system in SiGe/Si/SiGe quantum wel…
Triple-top-gate technique for studying the strongly interacting 2D electron systems in heterostructures
M. Yu. Melnikov, A. A. Shashkin, S. -H. Huang +2
We have developed a technique that dramatically reduces the contact resistances and depletes a shunting channel between the contacts outside the Hall bar in ultra-high mobility SiG…
Collective depinning and sliding of a quantum Wigner solid in a 2D electron system
M. Yu. Melnikov, A. A. Shashkin, S. -H. Huang +2
We report the observation of two-threshold voltage-current characteristics accompanied by a peak of broadband current noise between the two threshold voltages in the insulating sta…
Spin independence of the strongly enhanced effective mass in ultra-clean SiGe/Si/SiGe two-dimensional electron system
M. Yu. Melnikov, A. A. Shakirov, A. A. Shashkin +3
The effective mass at the Fermi level is measured in the strongly interacting two-dimensional (2D) electron system in ultra-clean SiGe/Si/SiGe quantum wells in the low-temperature…
Density dependence of the excitation gaps in an undoped Si/SiGe double-quantum-well heterostructure
D. Chen, S. Cai, N. -W. Hsu +7
We report low-temperature magneto-transport measurements of an undoped Si/SiGe asymmetric double quantum well heterostructure. The density in both layers is tuned independently uti…
Spin effect on the low-temperature resistivity maximum in a strongly interacting 2D electron system
A. A. Shashkin, M. Yu. Melnikov, V. T. Dolgopolov +6
The increase in the resistivity with decreasing temperature followed by a drop by more than one order of magnitude is observed on the metallic side near the zero-magnetic-field met…
Valley effects on the fractions in an ultrahigh mobility SiGe/Si/SiGe two-dimensional electron system
V. T. Dolgopolov, M. Yu. Melnikov, A. A. Shashkin +3
We observe minima of the longitudinal resistance corresponding to the quantum Hall effect of composite fermions at quantum numbers , 2, 3, 4, and 6 in an ultraclean strongly i…
Manifestation of strong correlations in transport in ultra-clean SiGe/Si/SiGe quantum wells
A. A. Shashkin, M. Yu. Melnikov, V. T. Dolgopolov +6
We observe that in a strongly interacting two-dimensional electron system in ultra-clean SiGe/Si/SiGe quantum wells, the resistivity on the metallic side near the metal-insulator t…
Metallic state in a strongly interacting spinless two-valley electron system in two dimensions
M. Yu. Melnikov, A. A. Shashkin, V. T. Dolgopolov +4
We have studied the strongly interacting, two-valley two-dimensional (2D) electron system in ultrahigh mobility SiGe/Si/SiGe quantum wells in parallel magnetic fields strong enough…
Fractional Quantum Hall Effect in SiGe/Si/SiGe Quantum Wells in Weak Quantizing Magnetic Fields
V. T. Dolgopolov, M. Yu. Melnikov, A. A. Shashkin +3
We have experimentally studied the fractional quantum Hall effect (FQHE) in SiGe/Si/SiGe quantum wells in relatively weak magnetic fields, where the Coulomb interaction between ele…
Effective g factor of low-density two-dimensional holes in a Ge quantum well
T. M. Lu, C. T. Harris, S. -H. Huang +3
We report measurements of the effective factor of low-density two-dimensional holes in a Ge quantum well. Using the temperature dependence of the Shubnikov-de Haas oscillations…
Density-controlled quantum Hall ferromagnetic transition in a two-dimensional hole system
T. M. Lu, L. A. Tracy, D. Laroche +5
Quantum Hall ferromagnetic transitions are typically achieved by increasing the Zeeman energy through in-situ sample rotation, while transitions in systems with pseudo-spin indices…
Unusual anisotropy of inplane field magnetoresistance in ultra-high mobility SiGe/Si/SiGe quantum wells
M. Yu. Melnikov, V. T. Dolgopolov, A. A. Shashkin +3
We find an unusual anisotropy of the inplane field magnetoresistance in ultra-high mobility SiGe/Si/SiGe quantum wells. The anisotropy depends on the orientation between the inplan…
Indication of band flattening at the Fermi level in a strongly correlated electron system
M. Yu. Melnikov, A. A. Shashkin, V. T. Dolgopolov +3
Using ultra-high quality SiGe/Si/SiGe quantum wells at millikelvin temperatures, we experimentally compare the energy-averaged effective mass, , with that at the Fermi level, $m…
Ultra-high mobility two-dimensional electron gas in a SiGe/Si/SiGe quantum well
M. Yu. Melnikov, A. A. Shashkin, V. T. Dolgopolov +3
We report the observation of an electron gas in a SiGe/Si/SiGe quantum well with maximum mobility up to 240 m^2/Vs, which is noticeably higher than previously reported results in s…
The effective electron mass in high-mobility SiGe/Si/SiGe quantum wells
M. Yu. Melnikov, A. A. Shashkin, V. T. Dolgopolov +3
The effective mass, m*, of the electrons confined in high-mobility SiGe/Si/SiGe quantum wells has been measured by the analysis of the temperature dependence of the Shubnikov-de Ha…